Cell and Developmental Biology Commons^™

Analogous Cellular Contribution And Healing Mechanisms Following Digit Amputation And Phalangeal Fracture In Mice, Lindsay A. Dawson, Jennifer Simkin, Michelle Sauque, Maegan Pela, Teresa Palkowski, Ken Muneoka

Biology Faculty Publications

Regeneration of amputated structures is severely limited in humans and mice, with complete regeneration restricted to the distal portion of the terminal phalanx (P3). Here, we investigate the dynamic tissue repair response of the second phalangeal element (P2) post amputation in the adult mouse, and show that the repair response of the amputated bone is similar to the proximal P2 bone fragment in fracture healing. The regeneration-incompetent P2 amputation response is characterized by periosteal endochondral ossification resulting in the deposition of new trabecular bone, corresponding to a significant increase in bone volume; however, this response is not associated with bone …

Chamber-Specific Patterns Of Epicardium Formation In Zebrafish, Sana Khan

Dissertations, Theses, and Capstone Projects

The outer cardiac layer, the epicardium, coordinates the final steps of vertebrate heart development. This cardiac tissue arises from cells in the proepicardial organ (PEO) that forms around the base of the inflow tract. Its general location is conserved across species despite morphological differences. Cellular mechanisms of migration differ across species. Three strategies of PEO migration are described: 1) The floating cyst model - PEO cells released into the pericardial cavity are directed by fluid movements to migrate onto the myocardium; 2) Villi transfer - cardiac contractions may mediate multicellular PEO villi contact to the myocardium; and 3) Tissue bridge-mediated …

Deciphering The Role Of Gfi1b Gene Target Rgs18 In Erythro-Megakaryocytic Lineage Divergence, Ananya Sengupta

Dissertations, Theses, and Capstone Projects

The molecular programs that govern the specification of erythroid and megakaryocytic lineages remain incompletely defined. Gene targeting experiments have shown the transcriptional repressor Gfi (Growth factor independence) 1b to be essential for the generation of both erythroid and megakaryocyte cells. Transcriptional repression of Gfi1b target genes is mediated mainly by the cofactors LSD (lysine demethylase) 1 and CoREST/Rcor1 (REST corepressor 1) or other Rcor factors. To understand the mechanism of Gfi1b action, its target genes were identified by chromatin immunoprecipitation (ChIP on Chip) screens. In this study we present the role of Rgs18 (Regulator of G protein signaling 18), a …

Decorin As A Multivalent Therapeutic Agent Against Cancer., Thomas Neill, Liliana Schaefer, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin is a prototypical small leucine-rich proteoglycan that epitomizes the multifunctional nature of this critical gene family. Soluble decorin engages multiple receptor tyrosine kinases within the target-rich environment of the tumor stroma and tumor parenchyma. Upon receptor binding, decorin initiates signaling pathways within endothelial cells downstream of VEGFR2 that ultimately culminate in a Peg3/Beclin 1/LC3-dependent autophagic program. Concomitant with autophagic induction, decorin blunts capillary morphogenesis and endothelial cell migration, thereby significantly compromising tumor angiogenesis. In parallel within the tumor proper, decorin binds multiple RTKs with high affinity, including Met, for a multitude of oncosuppressive functions including growth inhibition, tumor cell …

High Genetic Diversity But Low Population Structure In The Frog Pseudopaludicola Falcipes (Hensel, 1867) (Amphibia, Anura) From The Pampas Of South America, José A. Langone, Arley Camargo, Rafael O. De Sá

Biology Faculty Publications

Relative to South America’s ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is …

Role Of Bec-1/Beclin 1 And Autophagy Genes In C.Elegans Germline Cell Proliferation, Kristina Ames

Dissertations, Theses, and Capstone Projects

Autophagy is an evolutionary conserved process involved in the cellular adaptation to stress and basal levels of autophagy are crucial for cellular metabolism and homeostasis. Cellular recycling by autophagy is characterized by the formation of distinctive double-membrane vesicles (autophagosomes) that engulf unnecessary cytoplasmic components, such as organelles and long-lived proteins. Failure to remove protein aggregates and/or damaged organelles, via autophagy, has been implicated in various medical conditions such as liver disease, neurodegenerative diseases and cancer. Autophagy may suppress or promote cellular proliferation in tumors, depending on the type and metabolic state of the cell, where autophagy is generally believed to …

Lim Protein Ajuba Participates In The Repression Of Atr-Mediated Dna Damage Response In Human Cells, Sampada Kalan

Dissertations, Theses, and Capstone Projects

LIM proteins constitute a superfamily characterized by the presence of specialized domains called LIM. LIM domain is a unique double-zinc finger motif found in a variety of proteins and is mainly involved in protein-protein interactions. Previous work has implicated that members of the Zyxin subfamily of LIM proteins, namely TRIP6 and LPP are involved in the repression of the DNA damage response (DDR) at telomeres. We further explore if another member from this family has an influence on DDR prevention in the cells. Here, we describe a novel role for Ajuba, a Zyxin family LIM protein, in repressing inappropriate activation …

Glial Contributions To Neural Function And Disease, Mn Rasband

Faculty, Staff and Students Publications

The nervous system consists of neurons and glial cells. Neurons generate and propagate electrical and chemical signals, whereas glia function mainly to modulate neuron function and signaling. Just as there are many different kinds of neurons with different roles, there are also many types of glia that perform diverse functions. For example, glia make myelin; modulate synapse formation, function, and elimination; regulate blood flow and metabolism; and maintain ionic and water homeostasis to name only a few. Although proteomic approaches have been used extensively to understand neurons, the same cannot be said for glia. Importantly, like neurons, glial cells have …

Eosinophilic Esophagitis In Children And Its Relationship With Parental Allergies: Texas Children's Hospital Experience, G Hiremath, D Byramji, A Pacheco, G Constantine, C Davis, R Shulman, A Olive

Faculty, Staff and Students Publications

BACKGROUND: Eosinophilic esophagitis (EoE) is an allergen-mediated, clinicopathological condition affecting all ages. The characteristics of children with EoE in the southwestern USA have not been fully described. Furthermore, very little is known about the relationship between parental allergies and risk of EoE in their offspring in this patient population. AIMS: To characterize children with EoE and to examine the relationship between prevalence of parental allergies and occurrence of EoE in their offspring at a single referral pediatric center in the southwestern USA. METHODS: Demographic and clinical information of 126 children (=18 years of age) with EoE was abstracted in a …

Early Rescue Of Interneuron Disease Trajectory In Developmental Epilepsies, Ms Siehr, Jl Noebels

Faculty, Staff and Students Publications

The discovery of over 150 monogenic epilepsies and advances in early genetic diagnoses have launched a search for molecular strategies and developmental timetables to reverse or even prevent the course of these debilitating brain disorders. Orthologous rodent models of key disease genes are providing important examples of the range of targets, and serve as valuable test systems for perinatal therapeutic approaches. While gene-specific analyses of single rare 'orphan' diseases are each narrow in scope, they illuminate downstream pathways converging onto interneurons, and treatments that strengthen inhibition during cortical maturation may provide broad protection against these seemingly disparate gene errors. Several …

Efficacy Of Psychosocial Interventions In Inducing And Maintaining Alcohol Abstinence In Patients With Chronic Liver Disease: A Systematic Review, A Khan, A Tansel, Dl White, Wt Kayani, Wt Bano, J Lindsay, Hb El-Serag, F Kanwal

Faculty, Staff and Students Publications

BACKGROUND & AIMS: We conducted a systematic review of efficacy of psychosocial interventions in inducing or maintaining alcohol abstinence in patients with chronic liver disease (CLD) and alcohol use disorder (AUD). METHODS: We performed structured keyword searches in PubMed, PsychINFO, and MEDLINE for original research articles that were published from January 1983 through November 2014 that evaluated the use of psychosocial interventions to induce or maintain alcohol abstinence in patients with CLD and AUD. RESULTS: We identified 13 eligible studies that comprised 1945 patients; 5 were randomized controlled trials (RCTs). Delivered therapies included motivational enhancement therapy, cognitive behavioral therapy (CBT), …

Identification Of Novel Cyclic Lipopeptides From A Positional Scanning Combinatorial Library With Enhanced Antibacterial And Antibiofilm Activities, Nina Bionda, Renee M. Fleeman, César De La Fuente-Núñez, Maria C. Rodriguez, Fany Reffuveille, Lindsey N. Shaw, Irena Pastar, Stephen C Davis, Robert E W Hancock, Predrag Cudic

Molecular Biosciences Faculty Publications

Treating bacterial infections can be difficult due to innate or acquired resistance mechanisms, and the formation of biofilms. Cyclic lipopeptides derived from fusaricidin/LI-F natural products represent particularly attractive candidates for the development of new antibacterial and antibiofilm agents, with the potential to meet the challenge of bacterial resistance to antibiotics. A positional-scanning combinatorial approach was used to identify the amino acid residues responsible for driving antibacterial activity, and increase the potency of these cyclic lipopeptides. Screening against the antibiotic resistant ESKAPE pathogens revealed the importance of hydrophobic as well as positively charged amino acid residues for activity of this class …

Gap Junction Mediated Mirna Intercellular Transfer And Gene Regulation: A Novel Mechanism For Intercellular Genetic Communication, Liang Zong, Yan Zhu, Ruqiang Liang, Hong-Bo Zhao

Otolaryngology--Head & Neck Surgery Faculty Publications

Intercellular genetic communication is an essential requirement for coordination of cell proliferation and differentiation and has an important role in many cellular processes. Gap junction channels possess large pore allowing passage of ions and small molecules between cells. MicroRNAs (miRNAs) are small regulatory RNAs that can regulate gene expression broadly. Here, we report that miRNAs can pass through gap junction channels in a connexin-dependent manner. Connexin43 (Cx43) had higher permeability, whereas Cx30 showed little permeability to miRNAs. In the tested connexin cell lines, the permeability to miRNAs demonstrated: Cx43 > Cx26/30 > Cx26 > Cx31 > Cx30 = Cx-null. However, consistent with a uniform …

Estrogen Receptor Alpha (Esr1)-Dependent Regulation Of The Mouse Oviductal Transcriptome, Katheryn L. Cerny, Rosanne A. C. Ribeiro, Myoungkun Jeoung, Chemyong Ko, Phillip J. Bridges

Animal and Food Sciences Faculty Publications

Estrogen receptor-α (ESR1) is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO) and without (wild-type, WT) a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the …

Measurement Of Elastic Modulus Of Collagen Type I Single Fiber, Pavel Dutov, Olga Antipova, Sameer Varma, Joseph P R O Orgel, Jay D Schieber

Molecular Biosciences Faculty Publications

Collagen fibers are the main components of the extra cellular matrix and the primary contributors to the mechanical properties of tissues. Here we report a novel approach to measure the longitudinal component of the elastic moduli of biological fibers under conditions close to those found in vivo and apply it to type I collagen from rat tail tendon. This approach combines optical tweezers, atomic force microscopy, and exploits Euler-Bernoulli elasticity theory for data analysis. This approach also avoids drying for measurements or visualization, since samples are freshly extracted. Importantly, strains are kept below 0.5%, which appear consistent with the linear …

Characterization Of Induced Pluripotent Stem Cell Microvesicle Genesis, Morphology And Pluripotent Content, Jing Zhou, Shima Ghoroghi, Alberto Benito-Martin, Hao Wu, Uchenna John Unachukwu, Linda Saxe Einbond, Sara Guariglia, Hector Peinado, Stephen Redenti

Publications and Research

Microvesicles (MVs) are lipid bilayer-covered cell fragments that range in diameter from 30 nm–1uM and are released from all cell types. An increasing number of studies reveal that MVs contain microRNA, mRNA and protein that can be detected in the extracellular space. In this study, we characterized induced pluripotent stem cell (iPSC) MV genesis, content and fusion to retinal progenitor cells (RPCs) in vitro. Nanoparticle tracking revealed that iPSCs released approximately 2200 MVs cell/hour in the first 12 hrs with an average diameter of 122 nm. Electron and light microscopic analysis of iPSCs showed MV release via lipid bilayer budding. …

Imaging Tumour Cell Heterogeneity Following Cell Transplantation Into Optically Clear Immune-Deficient Zebrafish, Qin Tang, John C. Moore, Myron S. Ignatius, Inês M. Tenente, Madeline N. Hayes, Elaine G. Garcia, Nora Torres Yordán, Caitlin Bourque, Shuning He, Jessica S. Blackburn, A. Thomas Look, Yariv Houvras, David M. Langenau

Molecular and Cellular Biochemistry Faculty Publications

Cancers contain a wide diversity of cell types that are defined by differentiation states, genetic mutations and altered epigenetic programmes that impart functional diversity to individual cells. Elevated tumour cell heterogeneity is linked with progression, therapy resistance and relapse. Yet, imaging of tumour cell heterogeneity and the hallmarks of cancer has been a technical and biological challenge. Here we develop optically clear immune-compromised rag2^E450fs (casper) zebrafish for optimized cell transplantation and direct visualization of fluorescently labelled cancer cells at single-cell resolution. Tumour engraftment permits dynamic imaging of neovascularization, niche partitioning of tumour-propagating cells in embryonal rhabdomyosarcoma, emergence of clonal …

Mir494 Reduces Renal Cancer Cell Survival Coinciding With Increased Lipid Droplets And Mitochondrial Changes, Punashi Dutta, Edward Haller, Arielle Sharp, Meera Nanjundan

Molecular Biosciences Faculty Publications

Background: miRNAs can regulate cellular survival in various cancer cell types. Recent evidence implicates the formation of lipid droplets as a hallmark event during apoptotic cell death response. It is presently unknown whether MIR494, located at 14q32 which is deleted in renal cancers, reduces cell survival in renal cancer cells and if this process is accompanied by changes in the number of lipid droplets.

Methods: 769-P renal carcinoma cells were utilized for this study. Control or MIR494 mimic was expressed in these cells following which cell viability (via crystal violet) and apoptotic cell numbers (via Annexin V/PI staining) were …

H2ax Deficiency Is Associated With Erythroid Dysplasia And Compromised Haematopoietic Stem Cell Function, Baobing Zhao, Timothy L. Tan, Yang Mei, Jing Yang, Yiting Yu, Amit Verma, Ying Liang, Juehua Gao, Peng Ji

Toxicology and Cancer Biology Faculty Publications

Myelodysplastic syndromes (MDS) are clonal disorders of haematopoiesis characterised by dysplastic changes of major myeloid cell lines. However, the mechanisms underlying these dysplastic changes are poorly understood. Here, we used a genetically modified mouse model and human patient data to examine the physiological roles of H2AX in haematopoiesis and how the loss of H2AX contributes to dyserythropoiesis in MDS. H2AX knockout mice showed cell-autonomous anaemia and erythroid dysplasia, mimicking dyserythropoiesis in MDS. Also, dyserythropoiesis was increased in MDS patients with the deletion of chromosome 11q23, where H2AX is located. Although loss of H2AX did not affect the early stage of …

Hyaluronidase And Hyaluronan Oligosaccharides Promote Neurological Recovery After Intraventricular Hemorrhage, Govindaiah Vinukonda, Preeti Dohare, Arslan Arshad, Muhammad T. Zia, Sanjeet Panda, Ritesh Korumilli, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in premature infants results in inflammation, arrested oligodendrocyte progenitor cell (OPC) maturation, and reduced myelination of the white matter. Hyaluronan (HA) inhibits OPC maturation and complexes with the heavy chain (HC) of glycoprotein inter-α-inhibitor to form pathological HA (HC-HA complex), which exacerbates inflammation. Therefore, we hypothesized that IVH would result in accumulation of HA, and that either degradation of HA by hyaluronidase treatment or elimination of HCs from pathological HA by HA oligosaccharide administration would restore OPC maturation, myelination, and neurological function in survivors with IVH. To test these hypotheses, we used the preterm rabbit model of …