Biology Commons^™

Engineering Of Ideal Systems For The Study And Direction Of Stem Cell Asymmetrical Division And Fate Determination, Martina Zamponi

Biomedical Engineering Theses & Dissertations

The cellular microenvironment varies significantly across tissues, and it is constituted by both resident cells and the macromolecules they are exposed to. Cues that the cells receive from the microenvironment, as well as the signaling transmitted to it, affect their physiology and behavior. This notion is valid in the context of stem cells, which are susceptible to biochemical and biomechanical signaling exchanged with the microenvironment, and which plays a fundamental role in establishing fate determination and cell differentiation events. The definition of the molecular mechanisms that drive stem cell asymmetrical division, and how these are modulated by microenvironmental signaling, is …

Bone Morphogenetic Proteins Shape TReg Cells, Piotr Kraj

Biological Sciences Faculty Publications

The transforming growth factor-β (TGF-β) family includes cytokines controlling cell behavior, differentiation and homeostasis of various tissues including components of the immune system. Despite well recognized importance of TGF-β in controlling T cell functions, the immunomodulatory roles of many other members of the TGF-β cytokine family, especially bone morphogenetic proteins (BMPs), start to emerge. Bone Morphogenic Protein Receptor 1α (BMPR1α) is upregulated by activated effector and Foxp3+ regulatory CD4+ T cells (Treg cells) and modulates functions of both of these cell types. BMPR1α inhibits generation of proinflammatory Th17 cells and sustains peripheral Treg cells. This finding underscores the importance of …

Tick Extracellular Vesicles Enable Arthropod Feeding And Promote Distinct Outcomes Of Bacterial Infection, Adela S. Oliva Chávez, Xiaowei Wang, Liron Marnin, Nathan K. Archer, Holly L. Hammond, Erin E. Mcclure Carroll, Dana K. Shaw, Brenden G. Tully, Amanda D. Buskirk, Shelby L. Ford, L. Rainer Butler, Preeti Shahi, Kateryna Morozova, Cristina C. Clement, Lauren Lawres, Anya J. O'Neal, Choukri Ben Mamoun, Kathleen L. Mason, Brandi E. Hobbs, Glen A. Scoles, Eileen M. Barry, Daniel E. Sonenshine, Utpal Pal, Jesus G. Valenzuela, Marcelo B. Sztein, Marcela F. Pasetti, Michael L. Levin, Michail Kotsyfakis, Steven M. Jay, Jason F. Huntley, Lloyd S. Miller, Laura Santambrogio, Joao H.F. Pedra

Biological Sciences Faculty Publications

Extracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles from Ixodes scapularis enable tick feeding and promote infection of the mildly virulent rickettsial agent Anaplasma phagocytophilum through the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tick Dermacentor andersoni mitigate microbial spreading caused by the lethal pathogen Francisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting …

Self And Microbiota-Derived Epitopes Induce Cd4⁺ T Cell Anergy And Conversion Into Cd4⁺Foxp3⁺ Regulatory Cells, Michal P. Kuczma, Edyta A. Szurek, Anna Cebula, Vu L. Ngo, Maciej Pietrzak, Piotr Kraj, Timothy L. Denning, Leszek Ignatowicz

Biological Sciences Faculty Publications

The physiological role of T cell anergy induction as a key mechanism supporting self-tolerance remains undefined, and natural antigens that induce anergy are largely unknown. In this report, we used TCR sequencing to show that the recruitment of CD4⁺CD44⁺Foxp3⁻CD73⁺FR4⁺ anergic (Tan) cells expands the CD4⁺Foxp3⁺ (Tregs) repertoire. Next, we report that blockade in peripherally-induced Tregs (pTregs) formation due to mutation in CNS1 region of Foxp3 or chronic exposure to a selecting self-peptide result in an accumulation of Tan cells. Finally, we show that microbial antigens from Akkermansia muciniphila …

Pthr1/Sox9 And Idh1/Idh2 Relative Expression In Primary Chondrocyte And Chondrosarcoma Cells Under The Synergistic Influence Of Inducible Hypoxia And Extracellular Acidosis, Kostika Vangjeli

Biological Sciences Theses & Dissertations

Cartilage cells (Chondrocytes) grow in rather unique environmental conditions in the human body. Cartilage is avascular tissue and lacks innervation. Its main source of nutrients is derived from the synovial fluid and/or perichondrium. Consequently, these cells must survive and thrive under hypoxic and acidic stressors. Published data suggests that there are a multitude of genes affected from either one of these two stressors or both. However, these factors are frequently overlooked in cartilage research, and results are reported in either normoxia/pH=7.0 conditions, or they only account for one of the conditions. The scope of this study is to examine how …

Bone Morphogenic Proteins Are Immunoregulatory Cytokines Controlling Foxp3+ TReg Cells, Lauren M. Browning, Caroline Miller, Michal Kuczma, Maciej Pietrzak, Yu Jing, Grzegorz Rempala, Pawel Muranski, Leszek Ignatowicz, Piotr Kraj

Bioelectrics Publications

Bone morphogenic proteins (BMPs) are members of the transforming growth factor β (TGF-β) cytokine family promoting differentiation, homeostasis, and self-renewal of multiple tissues. We show that signaling through the bone morphogenic protein receptor 1α (BMPR1α) sustains expression of FOXP3 in T_reg cells in peripheral lymphoid tissues. BMPR1α signaling promotes molecular circuits supporting acquisition and preservation of T_reg cell phenotype and inhibiting differentiation of pro-inflammatory effector Th1/Th17 CD4+ T cell. Mechanistically, increased expression of KDM6B (JMJD3) histone demethylase, an antagonist of the polycomb repressive complex 2, underlies lineage-specific changes of T cell phenotypes associated with abrogation of BMPR1α signaling. …

Dormant Pathogenic Cd4(+) T Cells Are Prevalent In The Peripheral Repertoire Of Healthy Mice, Anna Cebula, Michal Kuczma, Edyta Szurek, Maciej Pietrzak, Natasha Savage, Wessam R. Elhefnawy, Grzegorz Rempala, Piotr Kraj, Leszek Ignatowicz

Computer Science Faculty Publications

Thymic central tolerance eliminates most immature T cells with autoreactive T cell receptors (TCR) that recognize self MHC/peptide complexes. Regardless, an unknown number of autoreactive CD4+Foxp3⁻ T cells escape negative selection and in the periphery require continuous suppression by CD4+Foxp3⁺ regulatory cells (Tregs). Here, we compare immune repertoires of Treg-deficient and Treg-sufficient mice to find Tregs continuously constraining one-third of mature CD4⁺Foxp3⁻ cells from converting to pathogenic effectors in healthy mice. These dormant pathogenic clones frequently express TCRs activatable by ubiquitous autoantigens presented by class II MHCs on conventional dendritic cells, including selfpeptides that select …

Exosomes Mediate Zika Virus Transmission Through Smpd3 Neutral Sphingomyelinase In Cortical Neurons, Wenshuo Zhou, Michael Woodson, Michael B. Sherman, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

The harmful effects of ZIKA virus (ZIKV) infection are reflected by severe neurological manifestations such as microcephaly in neonates and other complications associated with Guillain-Barre syndrome in adults. The transmission dynamics of ZIKV in or between neurons, or within the developing brains of the foetuses are not fully understood. Using primary cultures of murine cortical neurons, we show that ZIKV uses exosomes as mediators of viral transmission between neurons. Cryo-electron microscopy showed heterogeneous population of neuronal exosomes with a size range of 30-200 nm. Increased production of exosomes from neuronal cells was noted upon ZIKV infection. Neuronal exosomes contained both …

Emerging Roles Of The Membrane Potential: Action Beyond The Action Potential, Lina Abdul Kadir, Michael Stacey, Richard Barrett-Jolley

Bioelectrics Publications

Whilst the phenomenon of an electrical resting membrane potential (RMP) is a central tenet of biology, it is nearly always discussed as a phenomenon that facilitates the propagation of action potentials in excitable tissue, muscle, and nerve. However, as ion channel research shifts beyond these tissues, it became clear that the RMP is a feature of virtually all cells studied. The RMP is maintained by the cell's compliment of ion channels. Transcriptome sequencing is increasingly revealing that equally rich compliments of ion channels exist in both excitable and non-excitable tissue. In this review, we discuss a range of critical roles …

Differential Gene Expression In Response To Hypoxia And Acidosis In Chest Wall Deformities And Chondrosarcoma, Jamie L. Durbin

Biological Sciences Theses & Dissertations

The importance of understanding how costal cartilage chondrocytes respond to stimuli such as oxidative stress and low pH has been largely overlooked in studies involving tissue culturing due to major differences between oxygen and pH levels during incubation and the natural environment of hyaline cartilage. Hyaline cartilage is avascular and naturally hypoxic which subsequently leads to increased glycolytic metabolism and ultimately causes a decrease in extracellular pH. To examine how healthy costal cartilage responds to these extreme growth conditions, we examined responses in three hyaline cartilage diseases. Our ability to identify the disease mechanisms responsible for pectus excavatum, pectus carinatum, …

Plasma Activated Air Mediates Gene Transfer, Chelsea M. Edelblute

Biological Sciences Theses & Dissertations

Cold plasma is produced when strong applied electric fields accelerate free electrons, which dissociate, excite, or ionize gaseous molecules [1]. The deposition of ions from the plasma source is dependent on power generation, input gas composition, and gas flow rate. In the presence of reactive species, the membrane of eukaryotic cells is compromised allowing for otherwise impermeant molecules, such as DNA, to enter the inner-cell milieu [2].

The efficacy of a novel cold plasma reactor based on shielded sliding discharge for the delivery of plasmid DNA was assessed. The device is entirely non-contact, wherein the plasma never directly touches the …

Mouse Oocyte Maturation And Embryo Development After Exposure To Vemurafenib (Plx4032), An Anti-Melanoma B-Raf V600e Inhibitor, Bo Liu

Theses and Dissertations in Biomedical Sciences

Vemurafenib is a selective B-Raf^V600E inhibitor in melanoma targeted therapy which also inhibits the wild type B- and C-Raf. In oocyte maturation, the C-Raf/MAPK pathway acts as an important self-enhancing and promoting system, w hereas in embryo development, the C-Raf/M APK pathway participates in pre- and post- implantation embryo proliferation and differentiation.

The hypothesis: Vemurafenib has detrimental effects on oocyte maturation and/or embryo development. Mouse oocytes and one cell (1C) mouse embryos were tested by ex vivo culturing with Vemurafenib in serial dilution. Oocytes were evaluated by cell cycle morphology, spindle formation and chromosomal alignment by im munofluorescence (IF) …

Treatment Of Aortic Heart Valve Conduit With Glutamine And Heat Shock As A Means To Deter The Constituent Cellular Population From Becoming Apoptotic, Alyce Marie Linthurst Jones

Theses and Dissertations in Biomedical Sciences

Cryopreserved allograft heart valves represent the best solution for a patient with a failing heart valve. However, the constituent cells become apoptotic and within months of transplant the heart valve becomes acellular and the recipient's cells do not repopulate the allograft (3, 51). A strategy to prevent this situation would be to minimize or prevent apoptosis from occurring by strategically altering steps during heart valve processing. Recently it has been demonstrated that: 1) Heat shock protein 70 is a negative modulator of the apoptotic cascade; 2) Cells in culture exposed to hypothermic conditions produce heat shock protein 70 upon rewarming; …

Inhibition Of Voltage-Gated Na+ Current By Nanosecond Pulsed Electric Field (Nspef) Is Not Mediated By Na+ Influx Or Ca²+ Signaling, Vasyl Nesin, Andrei G. Pakhomov

Bioelectrics Publications

In earlier studies, we found that permeabilization of mammalian cells with nsPEF was accompanied by prolonged inhibition of voltage-gated (VG) currents through the plasma membrane. This study explored if the inhibition of VG Na⁺ current (I_Na) resulted from (i) reduction of the transmembrane Na⁺ gradient due to its influx via nsPEF-opened pores, and/or (ii) downregulation of the VG channels by a Ca²⁺ -dependent mechanism. We found that a single 300?ns electric pulse at 1.65.3?kV/cm triggered sustained Na⁺ influx in exposed NG108 cells and in primary chromaffin cells, as detected by increased fluorescence of a …

A Preliminary Study On The Potential Of Manuka Honey And Platelet-Rich Plasma In Wound Healing, Scott A. Sell, Patricia S. Wolfe, Andrew J. Spence, Isaac A. Rodriguez, Jennifer M. Mccoll, Rebecca L. Petrella, Koyal Garg, Jeffery J. Ericksen, Gary L. Bowlin

Nursing Faculty Publications

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, …

Analysis Of Biological Features Associated With Meiotic Recombination Hot And Cold Spots In Saccharomyces Cerevisiae, Loren Hansen, Nak-Kyeong Kim, Leonardo Mariño-Ramírez, David Landsman

Mathematics & Statistics Faculty Publications

Meiotic recombination is not distributed uniformly throughout the genome. There are regions of high and low recombination rates called hot and cold spots, respectively. The recombination rate parallels the frequency of DNA double-strand breaks (DSBs) that initiate meiotic recombination. The aim is to identify biological features associated with DSB frequency. We constructed vectors representing various chromatin and sequence-based features for 1179 DSB hot spots and 1028 DSB cold spots. Using a feature selection approach, we have identified five features that distinguish hot from cold spots in Saccharomyces cerevisiae with high accuracy, namely the histone marks H3K4me3, H3K14ac, H3K36me3, and H3K79me3; …

Determination Of Nuclear Factor-Kappa B Activation In Cultured Renal Epithelial Cells And Cardiac Myocytes Exposed To Cocaine And Morphine, David Angeles Tiangco

Biological Sciences Theses & Dissertations

Nuclear factor-kappa B (NF-kB) is an important transcription factor that participates in the genetic regulation of inflammation in many tissues. Cocaine and heroin are drugs of abuse associated with renal and cardiac pathology. The purpose of this study was to test the hypothesis that exposure to cocaine or morphine (a metabolite of heroin) would activate NF-kB in renal epithelial cells (COS-7) and cardiac myocytes (H9c2) grown in culture. COS-7 and H9c2 cells were co-transfected with an experimental reporter specific for NF-kB activation and a control reporter with constitutive activity. A dual-luciferase assay was used to determine levels of NF-kB activation …

In Vivo Effect Of Leukemia Inhibitory Factor (Lif) And An Anti-Lif Polyclonal Antibody On Murine Embryo And Fetal Development Following Exposure At The Time Of Transcervical Blastocyst Transfer, Michael H. Mitchell, R. James Swanson, Sergio Oehninger

Biological Sciences Faculty Publications

Leukemia inhibitory factor (LIF) enhances in vitro murine preimplantation development in a time- and dose-dependent fashion. Knockout experiments have demonstrated that endometrial LIF is essential for in vivo murine implantation. We assessed the impact of LIF and an anti-LIF polyclonal antibody (pab) on in vivo development and developed a novel and successful nonsurgical method of embryo transfer for this species, a transcervical blastocyst transfer technique. The objectives of this study were to evaluate the effects of LIF and the anti-LIF pab on 1) implantation, resorption, pregnancy, and viability rates and 2) the overall structural and skeletal development. Two-cell embryos were …

Efficacy Of AllowashTm Solution In Solubilization Of Bone Marrow, Alyce Marie Linthurst

Biological Sciences Theses & Dissertations

LifeNet currently cleans allograft bone utilizing Allowash^TM Technology, which encompasses the use of a closed continuous circulation chamber to remove bone marrow by flushing it with Allowash^TM Solution for a prescribed time and temperature after which, it is rinsed with various solutions to remove residual detergent that could be toxic to the recipient. A portion of this process employs Allowash^TM Solution to improve the solubilization and removal of protein and cellular elements in the red bone marrow. This study examines the effectiveness of Allowash^TM Solution in comparison to its component detergents Nonidet P40, Nonoxynol 9 and …

The Evaluation Of Succinylcholine Chloride For Harmful Effects Upon Early-Stage Mouse Embryos, Francis Warren Prescott

Biological Sciences Theses & Dissertations

Succinylcholine (SCh) chloride is a depolarizing neuromuscular blocking agent used to paralyze patients for surgical procedures. Over 1,800 clinical observations of newborn infants have demonstrated that succinylcholine does not cross the placenta in quantities detrimental to fetuses (Kolstad, et al., 1957, Bakhoum, et al., 1957, Hodges, et al., 1959, Duffield, et al., 1958, Dennis, et al., 1954, 1956, McNab, 1955, Coleman, et al., 1956, Lund, 1953). Later investigations which involved comparison of blood levels of SCh in the mother to those in fetuses bolstered the finding that SCh fails to cross the placenta in significant amounts (Moya and Kvisselgaard, 1961, …

Retention Of Cellular Viability And Growth Potential In Cryopreserved Bovine Arterial Tissue: Implications For Clinical Use Of Cryopreserved Vascular Allografts, Kip G. Gardner

Biological Sciences Theses & Dissertations

Segments of bovine calf aortas and pulmonary arteries were cryopreserved at -196° C for two weeks to 18 months and subsequently thawed. Cellular morphology, viability, and growth potential in these segments were then compared with the same attributes in segments from fresh (control) arteries. Scanning electron microscopy revealed no disruption of intimal surfaces attributable to cryopreservation. Endothelial cells were successfully cultured from all cryopreserved arterial segments. Endothelial monolayers grown from cryopreserved arteries had a cobblestone appearance and expressed Factor VIII antigen but not smooth muscle alpha-actin. Plating efficiency in primary cultures of endothelial cells was lower for cryopreserved arteries than …

Osteoinductivity Of Demineralized Bone: A Quantitative In Vitro Assessment, Yihong Zheng

Biological Sciences Theses & Dissertations

Acid demineralized bone (DMB) implanted in extraosseous sites induces bone formation. In vivo studies have shown that DMB stimulates the differentiation of mesenchymal cells into osteogenic cells. In this study an in vitro system was developed to demonstrate the osteoinductivity of DMB quantitatively. This in vitro working system was used to assess the osteoinductivity of variously processed DMB products as a means to evaluate their processing protocols. A human dermal fibroblastic (HDF) cell line was initiated from tissue explants as a working model, along with a human periosteal (HPO) cell line as a control. Ground DMB processed by LifeNet Transplant …

Fertilization And Mouse Embryo Development In The Presence Of Midazolam, Maria Leavitt

Biological Sciences Theses & Dissertations

The development of mouse embryos in vitro has provided a unique opportunity for the study of cellular differentiation and the influence of various agents on differentiation. Midazolam is administered for conscious sedation in the recovery of human ova. In the Norfolk IVF Program, midazolam is found in varying concentrations in follicular fluid. Mouse embryo formation and development has been used to test midazolam's effect on fertilization and early development as a model of human in vitro fertilization and development. Midazolam' s effects were studied using varying doses of midazolam on (1) in vivo fertilization and subsequent cell division, and (2) …

Evidence Of A Neurogenic Component During Ige-Mediated Inflammation In Murine Skin, Victoria Jean Cavanaugh

Biological Sciences Theses & Dissertations

The direct stimulation of sensory nerves or the intradermal injection of neuropeptides triggers a cutaneous inflammatory response that involves the degranulation of mast cells. These neurogenic inflammatory reactions are physiologically similar to IgE-mediated hypersensitivity responses, which also depend on mast cells. Although non-antigenic stimuli distinguish neurogenic from IgE-mediated inflammation, the similarity of their effector stages suggested that peripheral nerves may also participate in lgE-mediated responses. To examine this hypothesis, IgE responses were elicited in denervated skin. A murine model was developed where the footpad was denervated by surgically removing a 2 mm segment of the sciatic nerve, proximal to the …

Microsurgical Fertilization Of Mammalian Eggs: An Assessment Of Clinical Utilization, Susan E. Lanzendorf

Theses and Dissertations in Biomedical Sciences

Microsurgical fertilization is the technique in which a spermatozoon or sperm nucleus is injected into the cytoplasm of an egg. To establish a foundation for the use of microsurgical fertilization as a means of treating infertility, this study evaluated the procedure in hamster and human eggs. Hamster sperm nuclei were microinjected into hamster eggs to determine the rate of abnormal fertilization and to ultrastructurally assess cellular damage by transmission electron microscopy. Hamster eggs were also injected with human spermatozoa obtained from fertile and infertile men to evaluate the fertilizing potential of the sperm cells. In addition, human eggs donated by …

Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland

Biological Sciences Theses & Dissertations

Acetylcholinesterase (AChE) activity in the neonatal rat brain was determined by histochemical localization and quantitative biochemical analysis. AChE-positive perikarya were concentrated in the neostriatum, globus pallidus, medial habenular nucleus, amygdaloid complex, various hypothalamic nuclei, gigantocellular and paragigantocellular reticular nuclei, raphe nuclei, locus coeruleus, and motor nuclei of cranial nerves III-VII and IX-XII. Some areas stained differently or not at all when compared with the adult rat brain. The effects of prenatal ethanol exposure on regional AChE activity were assessed by comparing enzyme levels in offspring exposed via maternal consumption of a liquid diet containing 35 percent ethanol derived calories. This …

Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoretic Studies Demonstrating Cytoplasmic Protein Components Unique To The Mycelial Phase And To The Yeast Phase Of Candida Albicans, Theresa Catherine Burgess

Biological Sciences Theses & Dissertations

Blastospore and mycelial cytoplasmic extracts from four strains of Candida albicans, varying in virulence, were compared by sodium dodecyl sulfate (SDS) polyacrylamide disc gel electrophoresis Cytoplasmic extracts were made by disrupting the cultures in a Braun homogenizer followed by ultracentrifugation. The supernatant fractions were then resolved on polyacrylamide gels containing SDS. Each of the preparations yielded a distinct pattern. There were mycelial specific and blastospore specific protein bands. There were more components resolved from the blastospore phase cytoplasmic extracts than from the mycelial phase cytoplasmic extracts. There were bands common to both phases. These results demonstrate protein components unique …

The Effects Of The Cyclic 3'5'-Monophosphate Of Adenosine And Its Dibutyryl Derivative On The In-Vitro Immunization Of Mouse Spleen Cell Suspensions, James A. Blanks

Biological Sciences Theses & Dissertations

Abstract unavailable.