Medicine and Health Sciences Commons^™

Expression Of Phosphodiesterase 6 (Pde6) In Human Breast Cancer Cells, Hongli Dong, Kevin P. Claffey, Stefan Brocke, Paul M. Epstein

UCHC Articles - Research

Considerable epidemiological evidence demonstrates a positive association between artificial light at night (LAN) levels and incidence rates of breast cancer, suggesting that exposure to LAN is a risk factor for breast cancer. There is a 30-50% higher risk of breast cancer in the highest LAN exposed countries compared to the lowest LAN countries, and studies showing higher incidence of breast cancer among shift workers exposed to more LAN have led the International Agency for Research on Cancer to classify shift work as a probable human carcinogen. Nevertheless, the means by which light can affect breast cancer is still unknown. In …

One-Day Treatment Of Small Molecule 8-Bromo-Cyclic Amp Analogue Induces Cell-Based Vegf Production For In Vitro Angiogenesis And Osteoblastic Differentiation, Kevin W.-H. Lo, Ho Man Kan, Keith A. Gagnon, Cato T. Laurencin

UCHC Articles - Research

Small molecule based regenerative engineering is emerging as a promising strategy for regenerating bone tissue. Small molecule cAMP analogues have been proposed as novel biofactors for bone repair and regeneration, and while promising, the effect that these small molecules have on angiogenesis, a critical requirement for successful bone regeneration, is still unclear. Our previous research demonstrated that the small molecule cAMP analogue 8-bromoadenosine-3’,5’-cyclic monophosphate (8-Br-cAMP) was able to promote initial osteoblast adhesion on a polymeric scaffold via cAMP signaling cascades. Here, we report that 8-Br-cAMP is capable of inducing in vitro cell-based VEGF production for angiogenesis promotion. We first demonstrated …

Microglial Responses After Ischemic Stroke And Intracerebral Hemorrhage, Roslyn A. Taylor, Lauren H. Sansing

UCHC Articles - Research

Stroke is a leading cause of death worldwide. Ischemic stroke is caused by blockage of blood vessels in the brain leading to tissue death, while intracerebral hemorrhage (ICH) occurs when a blood vessel ruptures, exposing the brain to blood components. Both are associated with glial toxicity and neuroinflammation. Microglia, as the resident immune cells of the central nervous system (CNS), continually sample the environment for signs of injury and infection. Under homeostatic conditions, they have a ramified morphology and phagocytose debris. After stroke, microglia become activated, obtain an amoeboid morphology, and release inflammatory cytokines (the M1 phenotype). However, microglia can …

Preosteocytes/Osteocytes Have The Potential To Dedifferentiate Becoming A Source Of Osteoblasts, Elena Torreggiani, Brya G. Matthews, Slavica Pejda, Igor Matic, Danka Grcevic, Mark C. Horowitz, Ivo Kalajzic

UCHC Articles - Research

Presently there is no clear evidence for the ability of mature osteogenic lineage cells to dedifferentiate. In order to identify and trace mature osteogenic lineage cells, we have utilized transgenic mouse models in which the dentin matrix protein 1 (Dmp1) promoter drives expression of GFP (active marker) or Cre recombinase (historic label) in preosteocytes/osteocytes. In long bone chip outgrowth cultures, in which cells on the bone surface were enzymatically removed, cells with previous activity of the Dmp1 promoter migrated onto plastic and down-regulated Dmp1-GFP expression. Dmp1Cre-labeled cells from these cultures had the potential to re-differentiate into the osteogenic lineage, while …

Can Stem Cells Be Used To Generate New Lungs? Ex Vivo Lung Bioengineering With Decellularized Whole Lung Scaffolds, Todd J. Jensen, Eric D. Girard, Christine M. Finck

UCHC Articles - Research

For patients with end-stage lung diseases, lung transplantation is the only available therapeutic option. However, the number of suitable donor lungs is insufficient and lung transplants are complicated by significant graft failure and complications of immunosuppressive regimens. An alternative to classic organ replacement is desperately needed. Engineering of bioartificial organs using either natural or synthetic scaffolds is an exciting new potential option for generation of functional pulmonary tissue for human clinical application. Natural organ scaffolds can be generated by decellularization of native tissues; these acellular scaffolds retain the native organ ultrastructure and can be seeded with autologous cells toward the …

Osterix-Cre Labeled Progenitor Cells Contribute To The Formation And Maintenance Of The Bone Marrow Stroma, Yaling Liu, Sara Strecker, Liping Wang, Mark S. Kronenberg, Wen Wang, David W. Rowe, Peter F. Maye

UCHC Articles - Research

We have carried out fate mapping studies using Osterix-EGFPCre and Osterix-CreERt animal models and found Cre reporter expression in many different cell types that make up the bone marrow stroma. Constitutive fate mapping resulted in the labeling of different cellular components located throughout the bone marrow, whereas temporal fate mapping at E14.5 resulted in the labeling of cells within a region of the bone marrow. The identity of cell types marked by constitutive and temporal fate mapping included osteoblasts, adipocytes, vascular smooth muscle, perineural, and stromal cells. Prolonged tracing of embryonic precursors labeled at E14.5dpc revealed the continued …

Utilization Of Transgenic Models In Evaluation Of Osteogenic Differentiation Of Embryonic Stem Cells, Dario Repic, Elena Torreggiani, Tiziana Franceschetti, Brya G. Matthews, Alexander C. Lichtler, Ivo Kalajzic

UCHC Articles - Research

Previous studies reported that embryonic stem cells (ESCs) can be induced to differentiate into cells showing a mature osteoblastic phenotype by culturing them under osteo-inductive conditions. It is probable that osteogenic differentiation requires that ESCs undergo differentiation through an intermediary step involving a mesenchymal lineage precursor. Based on our previous studies indicating that adult mesenchymal progenitor cells express αSMA, we have generated ESCs from transgenic mice in which an αSMA promoter directs the expression of red fluorescent protein (RFP) to mesenchymal progenitor cells. To track the transition of ESC-derived MSCs into mature osteoblasts, we have utilized a bone-specific fragment of …

The Effects Of Estrogen In Ischemic Stroke, Louise D. Mccullough, Edward C. Koellhoffer

UCHC Articles - Research

Stroke is a leading cause of death and the most common cause of long-term disability in the USA. Women have a lower incidence of stroke compared with men throughout most of the lifespan which has been ascribed to protective effects of gonadal steroids, most notably estrogen. Due to the lower stroke incidence observed in pre-menopausal women and robust preclinical evidence of neuroprotective and anti-inflammatory properties of estrogen, researchers have focused on the potential benefits of hormones to reduce ischemic brain injury. However, as women age, they are disproportionately affected by stroke, coincident with the loss of estrogen with menopause. The …

Knockout Of Vascular Early Response Gene Worsens Chronic Stroke Outcomes In Neonatal Mice, Mehwish A. Mirza, Lori A. Capozzi, Yan Xu, Louise D. Mccullough, Fudong Liu

UCHC Articles - Research

Vascular early response gene (Verge) is a novel immediate early gene that is highly expressed during developmental angiogenesis and after ischemic insults in adult brain. However, the role of Verge after neonatal injury is not known. In the present study, we investigated the hypothesis that Verge contributes to vascular remodeling and tissue repair after neonatal ischemic injury. The Rice–Vanucci model (RVM) was employed to induce neonatal stroke in both Verge knockout (KO) and wild-type (WT) postnatal day 10 (P10) mice. Histological and behavioral outcomes at acute (24 h), subacute (7 days) and chronic (30 days) phases were evaluated. Angiogenesis, neurogenesis, …

Transgenic Sickle Cell Disease Mice Have High Mortality And Dysregulated Immune Responses After Vaccination, Steven M. Szczepanek, Eric R. Secor Jr, Sonali J. Bracken, Linda Guernsey, Ektor Rafti, Adam Matson, Roger S. Thrall

UCHC Articles - Research

Background

Children with sickle cell disease (SCD) are susceptible to recurrent infections, which are often life threatening and necessitate frequent vaccinations. Given the altered baseline immunity and proinflammatory state associated with SCD, we sought to determine the relative safety and efficacy of vaccination in transgenic SCD mice.

Methods

Eight week-old SCD mice were vaccinated with ovalbumin (OVA) and aluminum hydroxide weekly for three weeks by the intraperitoneal (IP) or intramuscular (IM) route. One week after the third vaccination, serum cytokines/chemokines, immunoglobulins, and bronchoalveolar lavage (BAL) fluid cytokines were measured.

Results

Only SCD mice were prone to mortality associated with vaccination …

Ptpn11 Deletion In A Novel Cartilage Cell Causes Metachondromatosis By Activating Hedgehog Signaling, Qian Wu

UCHC Articles - Research

SHP2, encoded by PTPN11, is required for survival, proliferation and differentiation of various cell types^1,2. Germ line activating mutations in PTPN11 cause Noonan Syndrome, while somatic PTPN11 mutations cause childhood myeloproliferative disease and contribute to some solid tumors. Recently, heterozygous inactivating mutations in PTPN11 were found in metachondromatosis, a rare inherited disorder featuring multiple exostoses, endochondromas, joint destruction and bony deformities^3,4. The detailed pathogenesis of this disorder has remained unclear. Here, we used a conditional knockout allele (Ptpn11^fl) and Cre recombinase (Cre) transgenic mice to delete Ptpn11 specifically in …

The Transcriptomics To Proteomics Of Hair Cell Regeneration: Looking For A Hair Cell In A Haystack, Gopinath Rajadinakaran

UCHC Articles - Research

Mature mammals exhibit very limited capacity for regeneration of auditory hair cells, while all non-mammalian vertebrates examined can regenerate them. In an effort to find therapeutic targets for deafness and balance disorders, scientists have examined gene expression patterns in auditory tissues under different developmental and experimental conditions. Microarray technology has allowed the large-scale study of gene expression profiles (transcriptomics) at whole-genome levels, but since mRNA expression does not necessarily correlate with protein expression, other methods, such as microRNA analysis and proteomics, are needed to better understand the process of hair cell regeneration. These technologies and some of the results of …

Subtelomeric Hotspots Of Aberrant 5-Hydroxymethylcytosine-Mediated Epigenetic Modifications During Reprogramming To Pluripotency, Stormy J. Chamberlain, I-Ping Chen

UCHC Articles - Research

Mammalian somatic cells can be directly reprogrammed into induced pluripotent stem cells (iPSCs) by introducing defined sets of transcription factors. Somatic cell reprogramming involves epigenomic reconfiguration, conferring iPSCs with characteristics similar to embryonic stem cells (ESCs). Human ES cells contain 5-hydroxymethylcytosine (5hmC), which is generated through the oxidation of 5-methylcytosine by the TET enzyme family. Here we show that 5hmC levels increase significantly during reprogramming to human iPSCs mainly due to TET1 activation, and this hydroxymethylation change is critical for optimal epigenetic reprogramming, but does not compromise primed pluripotency. Compared with hES cells, we find iPS cells tend to form …

Mmp-3 Mediates Psychosine-Induced Globoid Cell Formation: Implications For Leukodystrophy Pathology, Kumiko Ijichi, Graham D. Brown, Craig S. Moore, Paige N. Winokur, Roberto Pagarigan, Stephen J. Crocker

UCHC Articles - Research

Globoid cell leukodystrophy (GLD) or Krabbe disease, is a fatal demyelinating disease attributed to mutations in the galactocerebrosidase (GALC) gene. Loss of function mutations in GALC result in accumulation of the glycolipid intermediate, galactosylsphingosine (psychosine). Due to the cytotoxicity of psychosine, it has been hypothesized that accumulated psychosine underlie the pathophysiology of GLD. However, the cellular mechanisms of GLD pathophysiology remain unclear. Globoid cells, multinucleated microglia/macrophages in the central nervous system (CNS), are a defining characteristic of GLD. Here we report that exposure of primary glial cultures to psychosine induces the expression and the production of matrix metalloproteinase …

Racial And Ethnic Disparities In Diabetes Complications In The Northeastern United States: The Role Of Socioeconomic Status, Julie A. Wagner

UCHC Articles - Research

The role of socioeconomic status (SES) in explaining racial/ethnic disparities in diabetes remains unclear. We investigated disparities in self-reported diabetes complications, and the role of macro (e.g., income, education) and micro (e.g., ‘owning a home’ or ‘having a checking account’) SES indicators in explaining these differences. The sample included individuals with a diagnosis of diabetes (N=795) who were on average 55 years old, and 55.6% non-Hispanic White, 25.0% African American, and 19.4% Hispanic. Approximately 8% reported nephropathy, 35% reported retinopathy, and 16% reported cardiovascular disease. There were significant disparities in the rates of complications among non-Hispanic White, African American and …

The Sh2 Domain Interaction Landscape, Kazuya Machida, Christopher M. Thompson, Bruce J. Mayer

UCHC Articles - Research

Members of the SH2 domain family modulate signal transduction by binding to short peptides containing phosphorylated tyrosines. Each domain displays a distinct preference for the sequence context of the phosphorylated residue. We have developed a new high-density peptide chip technology that allows probing the affinity of most SH2 domains for a large fraction of the entire complement of tyrosine phosphopeptides in the human proteome. Using this technique we have experimentally identified thousands of putative SH2- peptide interactions for more than 70 different SH2 domains. By integrating this rich data set with orthogonal context-specific information, we have assembled an SH2 mediated …

Computationally Designed Peptide Inhibitors Against The Ubiquitin E3 Ligase Scf Fbx4, Bing Hao

UCHC Articles - Research

Telomerase is a reverse transcriptase that maintains telomere length. Telomerase activity is suppressed in somatic cells such that telomere attrition triggers replicative senescence or apop-tosis. In cancer cells, telomerase is up-regulated or reactivated, effectively making the cell immortal. Previous studies have shown that telomerase activity positively correlates with unfavorable cancer prognosis. Since it was discovered that activation of telomerase is a rate-limiting step in carcinogenesis, telomerase has gained much interest as a drug target. Both screening and structure-based methods have been extensively employed to identify small molecule leads that can selectively disrupt telomerase activity. Strategies commonly used to target telomerase …

A Potential New Pathway For Pd-L1 Costimulation Of The Cd8-T Cell Response To Listeria Monocytogenes Infection, Daqi Xu, Han-Hsuan Fu, Joshua J. Obar, Leo Lefrançois

UCHC Articles - Research

Programmed death ligand-1 (PD-L1) is an important negative regulator of T cell immune responses via interactions with PD-1 and CD80. However, PD-L1 can also act as a positive costimulator, but the relevant counterreceptor is not known. We analyzed the role of PD-L1 in CD8-T cell responses to infection with Listeria monocytogenes (LM) or vesicular stomatitis virus (VSV). PD-L1 blockade impaired antigen-specific CD8 effector T cell expansion in response to LM, but not to VSV infection, particularly limiting short-lived effector cell differentiation. Simultaneous CD4-T cell depletion and anti-PD-L1 blockade revealed that PD-L1 provided costimulation even in the absence of CD4-T cells. …

Resistive-Pulse Measurements With Nanopipettes: Detection Of Au Nanoparticles And Nanoparticle-Bound Anti-Peanut Igy†, Vigneshwaran Mani, Naimish Sardesai, James F. Rusling

UCHC Articles - Research

Solid-state nanopores have been widely employed in sensing applications from Coulter counters to DNA sequencing devices. The analytical signal in such experiments is the change in ionic current flowing through the orifice caused by the large molecule or nanoparticle translocation through the pore. Conceptually similar nanopipette-based sensors can offer several advantages including the ease of fabrication and small physical size essential for local measurements and experiments in small spaces. This paper describes the first evaluation of nanopipettes with well characterized geometry for resistive-pulse sensing of Au nanoparticles (AuNP), nanoparticles coated with an allergen epitope peptide layer, and AuNP–peptide particles with …

Transient Receptor Potential (Trp) Channels And Cardiac Fibrosis, Zhichao Yue, Yanhui Zhang, Jia Xie, Jianmin Jiang, Lixia Yue

UCHC Articles - Research

Cardiac fibrosis is associated with most cardiac diseases. Fibrosis is an accumulation of excessive extracellular matrix proteins (ECM) synthesized by cardiac fibroblasts and myofibroblasts. Fibroblasts are the most prevalent cell type in the heart, comprising 75% of cardiac cells. Myofibroblasts are hardly present in healthy normal heart tissue, but appear abundantly in diseased hearts. Cardiac fibroblasts are activated by a variety of pathological stimuli, such as myocardial injury, oxidative stress, mechanical stretch, and elevated autocrine-paracrine mediators, thereby undergoing proliferation, differentiation to myofibroblasts, and production of various cytokines and ECM proteins. A number of signaling pathways and bioactive molecules are involved …

Predictors Of Adherence To Home Rehabilitation Exercises Following Anterior Cruciate Ligament Reconstruction, Howard A. Tennen

UCHC Articles - Research

Purpose/Objective

Although home exercises are commonly prescribed following anterior cruciate ligament (ACL) reconstruction and are considered important in obtaining successful rehabilitation outcomes, little is known about factors associated with the completion of such exercises. Consequently, this study was designed to identify predictors of adherence to home rehabilitation exercises after ACL surgery.

Research Method/Design

Participants (33 women, 58 men) completed indices of athletic identity, neuroticism, optimism, and pessimism before ACL surgery and measures of daily pain, negative mood, stress, and home exercise completion for 42 days postoperatively.

Results

Participants reported a high level of adherence to the prescribed regimen. Home exercise …

Membrane Association Via An N-Terminal Amphipathic Helix Is Required For The Cellular Organization And Function Of Rnase Ii, Feng Lu, Aziz Taghbalout

UCHC Articles - Research

The subcellular localization of the exoribonuclease RNase II is not known despite the advanced biochemical characterization of the enzyme. Here we report that RNase II is organized into cellular structures that appear to coil around the Escherichia coli cell periphery and that RNase II is associated with the cytoplasmic membrane by its aminoterminal amphipathic helix. The helix also acts as an autonomous transplantable membranebinding domain capable of directing normally cytoplasmic proteins to the membrane. Assembly of the organized cellular structures of RNase II required the RNase II amphipathic membrane-binding domain. Coimmunoprecipitation of the protein from cell extracts indicated that RNase …

Preconditioning Induces Sustained Neuroprotection By Down Regulation Of Ampk, Louise D. Mccullough, Venugopal Reddy Venna, Jun Li, Sharon E. Benashski, Sami Tarabishy

UCHC Articles - Research

Abstract Background and Purpose—Ischemic preconditioning (IPC) induces endogenous neuroprotection from a subsequent ischemic injury. IPC involves down-regulation of metabolic pathways. As Adenosine 5′-monophosphate-activated protein kinase (AMPK) is a critical sensor of energy balance and plays a major role in cellular metabolism, its role in IPC was investigated.

Methods—A brief 3 minute middle cerebral artery occlusion (MCAO) was employed to induce IPC in male mice 72 hours prior to 90 minute MCAO. Levels of AMPK and pAMPK, the active form of the kinase, were assessed after IPC. A pharmacological activator or inhibitor of AMPK was utilized to determine the …

Computational Analysis Of Rho Gtpase Cycling, Cibele Vieira Falkenberg, Leslie M. Loew

UCHC Articles - Research

The Rho family of GTPases control actin organization during diverse cellular responses (migration, cytokinesis and endocytosis). Although the primary members of this family (RhoA, Rac and Cdc42) have different downstream effects on actin remodeling, the basic mechanism involves targeting to the plasma membrane and activation by GTP binding. Our hypothesis is that the details of GTPase cycling between membrane and cytosol are key to the differential upstream regulation of these biochemical switches. Accordingly, we developed a modeling framework to analyze experimental data for these systems. This analysis can reveal details of GDI-mediated cycling and help distinguish between GDI-dependent and -independent …

Coordinated Activation Of The Rac-Gap Β2-Chimaerin By An Atypical Proline-Rich Domain And Diacylglcercol, Bruce J. Mayer

UCHC Articles - Research

Chimaerins, a family of GTPase activating proteins (GAPs) for the small G-protein Rac, have been implicated in development, neuritogenesis, and cancer. These Rac-GAPs are regulated by the lipid second messenger diacylglycerol (DAG) generated by tyrosine-kinases such as the epidermal growth factor receptor (EGFR). Here we identify an atypical Pro-rich motif in chimaerins that binds to the adaptor protein Nck1. Unlike most Nck1 partners, chimaerins bind to the third SH3 domain of Nck1. This association is mediated by electrostatic interactions of basic residues within the Pro-rich motif with acidic clusters in the SH3 domain. EGF promotes the binding of β2-chimaerin to …

Neurogenesis Continues In The Third Trimester Of Pregnancy And Is Suppressed By Premature Birth, Nada Zecevic

UCHC Articles - Research

Premature infants exhibit neurodevelopmental delay and reduced growth of the cerebral cortex. However, the underlying mechanisms have remained elusive. Therefore, we hypothesized that neurogenesis in the ventricular and subventricular zones of the cerebral cortex would continue in the third trimester of pregnancy, and that preterm birth would suppress neurogenesis. To test our hypotheses, we evaluated autopsy materials from human fetuses and preterm infants of 16–35 gestational weeks (gw). We noted that both cycling and non-cycling Sox2⁺ radial glial cells as well as Tbr2⁺ intermediate progenitors were abundant in human preterm infants until 28 gw. However, their densities consistently …

Retrospective Study Of Microorganisms Associated With Vascular Access Infections In Hemodialysis Patients, Andre A. Kaplan, Richard S. Feinn, Rajesh V. Lalla

UCHC Articles - Research

Objective

To assess microorganisms associated with vascular access-associated infections (VAIs) in hemodialysis patients, with respect to possible origin from the mouth.

Study Design

A retrospective and comparative analysis of the microbes associated with VAI in hemodialysis patients treated during a 10-year period was performed using the Human Oral Microbiome Database (HOMD).

Results

Of 218 patient records identified, 65 patients collectively experienced 115 VAI episodes. The most common microorganisms involved were Staphylococcus aureus (49.6% of infections), Staphylococcus epidermidis (10.4%), Serratia marcescens (10.4%), Pseudomonas aeruginosa (9.6%), and Enterococcus faecalis / fecum (8.7%). None of these was found in 1% or more of …

Copper Signaling In The Mammalian Nervous System: Synaptic Effects, Eric D. Gaier, Betty A. Eipper, Richard E. Mains

UCHC Articles - Research

Copper (Cu) is an essential metal present at high levels in the CNS. Its role as a co-factor in mitochondrial ATP production and in other essential cuproenzymes is well defined. Menkes and Wilson’s diseases are severe neurodegenerative conditions that demonstrate the importance of Cu transport into the secretory pathway. Brain levels of Cu, which is almost entirely protein bound, exceed extracellular levels by more than a hundred-fold. Cu stored in the secretory pathway is released in a Ca²⁺-dependent manner and can transiently reach concentrations over 100 µM at synapses. The ability of low µM levels of Cu to …

Variation In Mu-Opioid Receptor Gene (Oprm1) As A Moderator Of Naltrexone Treatment To Reduce Heavy Drinking In A High Functioning Cohort, Jonathan M. Covault

UCHC Articles - Research

Background

It is well known that naltrexone, an FDA-approved medication for treatment of alcohol dependence, is effective for only a subset of individuals. Recent studies have examined the utility of a functional A118G single nucleotide polymorphism (SNP) of the mu-opioid receptor gene (OPRM1) as a predictor of naltrexone treatment response. Although the findings to date have generally been consistent with a moderating effect of the SNP, further evaluation of this hypothesis is warranted.

Objective

To evaluate whether problem drinkers with one or two copies of the 118G allele respond better to naltrexone treatment. The treatment goal in this cohort of …

Millon Behavioral Medicine Diagnostic (Mbmd) Predicts Health-Related Quality Of Life (Hrqol) Over Time Among Men Treated For Localized Prostate Cancer, Dean G. Cruess

UCHC Articles - Research

Prostate cancer treatment presents multiple challenges that can negatively affect health-related quality of life (HrQoL), and which may be further compromised by maladaptive personality styles and psychological adjustment difficulties. This study examined the utility of a comprehensive psychosocial screening tool to identify psychosocial traits that prospectively predict HrQoL status among men treated for localized prostate cancer. The Millon Behavioral Medicine Diagnostic (MBMD) was administered to 66 men (mean age 68 years, 59% Caucasian) treated by either radical prostatectomy or radiotherapy along with standard measures of general and prostate cancer-specific quality of life assessed at a 12-month follow-up. Higher scores on …