Medicine and Health Sciences Commons^™

The P2y(12) Antagonists, 2mesamp And Cangrelor, Inhibit Platelet Activation Through P2y(12)/G(I)-Dependent Mechanism, Binggang Xiang, Guoying Zhang, Hongmei Ren, Manjula Sunkara, Andrew J. Morris, T. Kent Gartner, Susan S. Smyth, Zhenyu Li

Saha Cardiovascular Research Center Faculty Publications

BACKGROUND: ADP is an important physiological agonist that induces integrin activation and platelet aggregation through its receptors P2Y(1) (Gα(q)-coupled) and P2Y(12) (Gα(i)-coupled). P2Y(12) plays a critical role in platelet activation and thrombosis. Adenosine-based P2Y(12) antagonists, 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (2MeSAMP) and Cangrelor (AR-C69931MX) have been widely used to demonstrate the role of P2Y(12) in platelet function. Cangrelor is being evaluated in clinical trials of thrombotic diseases. However, a recent study reported that both 2MeSAMP and Cangrelor raise intra-platelet cAMP levels and inhibit platelet aggregation through a P2Y(12)-independent mechanism.

METHODOLOGY/PRINCIPAL FINDINGS: The present work, using P2Y(12) deficient mice, sought to …

Evaluation Of Very High- And Very Low-Dose Intravitreal Aflibercept In Patients With Neovascular Age-Related Macular Degeneration., Quan Dong Nguyen, Peter A. Campochiaro, Syed Mahmood Shah, David J. Browning, Henry L. Hudson, Peter L. Sonkin, Seenu M. Hariprasad, Peter K. Kaiser, Jason Slakter, Julia A. Haller, Diana V. Do, William Mieler, Karen Chu, Avner Ingerman, Robert Vitti, Alyson J. Berliner, Jesse Cedarbaum, Clear-It 1 Investigators

Journal Articles: Ophthalmology

PURPOSE: To determine bioactivity and duration of effect of intravitreal aflibercept injection (also known as vascular endothelial growth factor Trap-Eye) for neovascular age-related macular degeneration (AMD).

METHODS: In this double-masked, phase 1 study, 28 patients with lesions ≤12 disc areas, ≥50% active choroidal neovascularization (CNV), and best corrected visual acuity (BCVA) ≤20/40 were randomized 1:1 to a single intravitreal injection of aflibercept 0.15 or 4 mg. The primary end point was the change from baseline in central retinal/lesion thickness (CR/LT) at week-8. Secondary outcomes were the change from baseline BCVA, the change in CNV lesion size and area of leakage, …

Fak Is A Critical Regulator Of Neuroblastoma Liver Metastasis, Sora Lee, Jingbo Qiao, Pritha Paul, Kathleen L. O'Connor, B. Mark Evers, Dai H. Chung

Surgery Faculty Publications

Neuroblastomas express increased levels of gastrin-releasing peptide receptor (GRP-R). However, the exact molecular mechanisms involved in GRP-R-mediated cell signaling in neuroblastoma growth and metastasis are unknown. Here, we report that focal adhesion kinase (FAK), as a critical downstream target of GRP-R, is an important regulator of neuroblastoma tumorigenicity. We found that FAK expression correlates with GRP-R expression in human neuroblastoma sections and cell lines. GRP-R overexpression in SK-N-SH cells increased FAK, integrin α3 and β1 expressions and cell migration. These cells demonstrated flatter cell morphology with broad lamellae, in which intense FAK expression was localized to the leading edges of …

Breast Cancer Incidence In Black And White Women Stratified By Estrogen And Progesterone Receptor Statuses., Michael X. Gleason, Tengiz Mdzinarishvili, Simon Sherman

Journal Articles: Eppley Institute

BACKGROUND: There is increasing evidence that breast cancer is a heterogeneous disease presented by different phenotypes and that white women have a higher breast cancer incidence rate, whereas black women have a higher mortality rate. It is also well known that white women have lower incidence rates than black women until approximately age 40, when rate curves cross over and white women have higher rates. The goal of this study was to validate the risk of white and black women to breast cancer phenotypes, stratified by statuses of the estrogen (ER) and progesterone (PR) receptors.

METHODOLOGY/PRINCIPAL FINDINGS: SEER17 data were …

Trop-2 Inhibits Prostate Cancer Cell Adhesion To Fibronectin Through The Β1 Integrin-Rack1 Axis., Marco Trerotola, Jing Li, Saverio Alberti, Lucia R. Languino

Department of Cancer Biology Faculty Papers

Trop-2 is a transmembrane glycoprotein upregulated in several human carcinomas, including prostate cancer (PrCa). Trop-2 has been suggested to regulate cell-cell adhesion, given its high homology with the other member of the Trop family, Trop-1/EpCAM, and its ability to bind the tight junction proteins claudin-1 and claudin-7. However, a role for Trop-2 in cell adhesion to the extracellular matrix has never been postulated. Here, we show for the first time that Trop-2 expression in PrCa cells correlates with their aggressiveness. Using either shRNA-mediated silencing of Trop-2 in cells that endogenously express it, or ectopic expression of Trop-2 in cells that …

Severe Stress Switches Crf Action In The Nucleus Accumbens From Appetitive To Aversive., Julia C Lemos, Matthew J Wanat, Jeffrey S Smith, Beverly A S Reyes, Nick G Hollon, Elisabeth J Van Bockstaele, Charles Chavkin, Paul E M Phillips

Farber Institute for Neuroscience Faculty Papers

Stressors motivate an array of adaptive responses ranging from 'fight or flight' to an internal urgency signal facilitating long-term goals. However, traumatic or chronic uncontrollable stress promotes the onset of major depressive disorder, in which acute stressors lose their motivational properties and are perceived as insurmountable impediments. Consequently, stress-induced depression is a debilitating human condition characterized by an affective shift from engagement of the environment to withdrawal. An emerging neurobiological substrate of depression and associated pathology is the nucleus accumbens, a region with the capacity to mediate a diverse range of stress responses by interfacing limbic, cognitive and motor circuitry. …

The Alternative Crosstalk Between Rage And Nitrative Thioredoxin Inactivation During Diabetic Myocardial Ischemia-Reperfusion Injury., Yi Liu, Yan Qu, Rutao Wang, Yanzhuo Ma, Chenhai Xia, Chao Gao, Jingyi Liu, Kun Lian, Aibing Xu, Xiaoyan Lu, Lu Sun, Lu Yang, Wayne B. Lau, Erhe Gao, Walter Koch, Haichang Wang, Ling Tao

Department of Emergency Medicine Faculty Papers

The receptor for advanced glycation end products (RAGE) and thioredoxin (Trx) play opposing roles in diabetic myocardial ischemia-reperfusion (MI/R) injury. We recently demonstrated nitrative modification of Trx leads to its inactivation and loss of cardioprotection. The present study is to determine the relationship between augmented RAGE expression and diminished Trx activity pertaining to exacerbated MI/R injury in the diabetic heart. The diabetic state was induced in mice by multiple intraperitoneal low-dose streptozotocin injections. RAGE small-interfering RNA (siRNA) or soluble RAGE (sRAGE, a RAGE decoy) was via intramyocardial and intraperitoneal injection before MI/R, respectively. Mice were subjected to 30 min of …

Perlecan Domain V Induces Vegf Secretion In Brain Endothelial Cells Through Integrin Α5Β1 And Erk-Dependent Signaling Pathways, Douglas N. Clarke, Abraham Al Ahmad, Boyeon Lee, Christi Parham, Lisa Auckland, Andrezj Fertala, Michael Kahle, Courtney S. Shaw, Jill Roberts, Gregory J. Bix

Sanders-Brown Center on Aging Faculty Publications

Perlecan Domain V (DV) promotes brain angiogenesis by inducing VEGF release from brain endothelial cells (BECs) following stroke. In this study, we define the specific mechanism of DV interaction with the α(5)β(1) integrin, identify the downstream signal transduction pathway, and further investigate the functional significance of resultant VEGF release. Interestingly, we found that the LG3 portion of DV, which has been suggested to possess most of DV's angio-modulatory activity outside of the brain, binds poorly to α(5)β(1) and induces less BEC proliferation compared to full length DV. Additionally, we implicate DV's DGR sequence as an important element for the interaction …

Perlecan Domain V Induces Vegf Secretion In Brain Endothelial Cells Through Integrin Α5Β1 And Erk-Dependent Signaling Pathways., Douglas N Clarke, Abraham Al Ahmad, Boyeon Lee, Christi Parham, Lisa Auckland, Andrezj Fertala, Michael Kahle, Courtney S Shaw, Jill Roberts, Gregory J Bix

Department of Dermatology and Cutaneous Biology Faculty Papers

Perlecan Domain V (DV) promotes brain angiogenesis by inducing VEGF release from brain endothelial cells (BECs) following stroke. In this study, we define the specific mechanism of DV interaction with the α(5)β(1) integrin, identify the downstream signal transduction pathway, and further investigate the functional significance of resultant VEGF release. Interestingly, we found that the LG3 portion of DV, which has been suggested to possess most of DV's angio-modulatory activity outside of the brain, binds poorly to α(5)β(1) and induces less BEC proliferation compared to full length DV. Additionally, we implicate DV's DGR sequence as an important element for the interaction …

Differential Effects Of Interleukin-17 Receptor Signaling On Innate And Adaptive Immunity During Central Nervous System Bacterial Infection., Debbie Vidlak, Tammy Kielian

Journal Articles: Pathology and Microbiology

Although IL-17A (commonly referred to as IL-17) has been implicated in the pathogenesis of central nervous system (CNS) autoimmune disease, its role during CNS bacterial infections remains unclear. To evaluate the broader impact of IL-17 family members in the context of CNS infection, we utilized IL-17 receptor (IL-17R) knockout (KO) mice that lack the ability to respond to IL-17, IL-17F and IL-17E (IL-25). In this article, we demonstrate that IL-17R signaling regulates bacterial clearance as well as natural killer T (NKT) cell and gamma-delta (γδ) T cell infiltrates during Staphylococcus aureus-induced brain abscess formation. Specifically, when compared with wild-type (WT) …

Transforming Growth Factor-Β Suppresses Metastasis In A Subset Of Human Colon Carcinoma Cells., Neka A.K. Simms, Ashwani Rajput, Elizabeth A. Sharratt, Melanie Ongchin, Carol A. Teggart, J. Wang, Michael G. Brattain

Journal Articles: Eppley Institute

BACKGROUND: TGFβ signaling has typically been associated with suppression of tumor initiation while the role it plays in metastasis is generally associated with progression of malignancy. However, we present evidence here for an anti-metastatic role of TGFβ signaling.

METHODS: To test the importance of TGFβ signaling to cell survival and metastasis we compared human colon carcinoma cell lines that are either non-tumorigenic with TGFβ response (FET), or tumorigenic with TGFβ response (FETα) or tumorigenic with abrogated TGFβ response via introduction of dominant negative TGFβRII (FETα/DN) and their ability to metastasize. Metastatic competency was assessed by orthotopic transplantation. Metastatic colony formation …

Effect Of Oxidative Stress On Protein Tyrosine Phosphatase 1b In Scleroderma Dermal Fibroblasts., Pei-Suen Tsou, Nadine N. Talia, Adam J. Pinney, Ann Kendzicky, Sonsoles Piera-Velazquez, Sergio A. Jimenez, James R. Seibold, Kristine Phillips, Alisa E Koch

Department of Dermatology and Cutaneous Biology Faculty Papers

OBJECTIVE: Platelet-derived growth factor (PDGF) and its receptor, PDGFR, promote fibrosis in systemic sclerosis (SSc; scleroderma) dermal fibroblasts, and such cells in scleroderma skin lesions produce excessive reactive oxygen species (ROS). PDGFR is phosphorylated upon PDGF stimulation, and is dephosphorylated by protein tyrosine phosphatases (PTPs), including PTP1B. This study was undertaken to determine whether the thiol-sensitive PTP1B is affected by ROS in SSc dermal fibroblasts, thereby enhancing the phosphorylation of PDGFR and synthesis of type I collagen. This study also sought to investigate the effect of a thiol antioxidant, N-acetylcysteine (NAC), in SSc.

METHODS: Fibroblasts were isolated from the skin …

Inhibition Of Soluble Tumor Necrosis Factor Ameliorates Synaptic Alterations And Ca2+ Dysregulation In Aged Rats, Diana M. Sama, Hafiz Mohmmad Abdul, Jennifer L. Furman, Irina A. Artiushin, David E. Szymkowski, Stephen W. Scheff, Christopher M. Norris

Graduate Center for Gerontology Faculty Publications

The role of tumor necrosis factor α (TNF) in neural function has been investigated extensively in several neurodegenerative conditions, but rarely in brain aging, where cognitive and physiologic changes are milder and more variable. Here, we show that protein levels for TNF receptor 1 (TNFR1) are significantly elevated in the hippocampus relative to TNF receptor 2 (TNFR2) in aged (22 months) but not young adult (6 months) Fischer 344 rats. To determine if altered TNF/TNFR1 interactions contribute to key brain aging biomarkers, aged rats received chronic (4-6 week) intracranial infusions of XPro1595: a soluble dominant negative TNF that preferentially inhibits …

Cardiac G-Protein-Coupled Receptor Kinase 2 Ablation Induces A Novel Ca2+ Handling Phenotype Resistant To Adverse Alterations And Remodeling After Myocardial Infarction., Philip W Raake, Xiaoying Zhang, Leif E Vinge, Henriette Brinks, Erhe Gao, Naser Jaleel, Yingxin Li, Mingxin Tang, Patrick Most, Gerald W Dorn, Steven R Houser, Hugo A Katus, Xiongwen Chen, Walter J Koch

Center for Translational Medicine Faculty Papers

BACKGROUND: G-protein-coupled receptor kinase 2 (GRK2) is a primary regulator of β-adrenergic signaling in the heart. G-protein-coupled receptor kinase 2 ablation impedes heart failure development, but elucidation of the cellular mechanisms has not been achieved, and such elucidation is the aim of this study.

METHODS AND RESULTS: Myocyte contractility, Ca(2+) handling and excitation-contraction coupling were studied in isolated cardiomyocytes from wild-type and GRK2 knockout (GRK2KO) mice without (sham) or with myocardial infarction (MI). In cardiac myocytes isolated from unstressed wild-type and GRK2KO hearts, myocyte contractions and Ca(2+) transients were similar, but GRK2KO myocytes had lower sarcoplasmic reticulum (SR) Ca(2+) content …

Il-1ri (Interleukin-1 Receptor Type I) Signalling Is Essential For Host Defence And Hemichannel Activity During Acute Central Nervous System Bacterial Infection., Juan Xiong, Maria Burkovetskaya, Nikolay Karpuk, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1) response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood-brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system) infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I) KO (knockout) animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared …

Essential Role Of Caveolin-3 In Adiponectin Signalsome Formation And Adiponectin Cardioprotection., Yajing Wang, Xiaoliang Wang, Jean-François Jasmin, Wayne Bond Lau, Rong Li, Yuexin Yuan, Wei Yi, Kurt Chuprun, Michael P. Lisanti, Walter J Koch, Erhe Gao, Xin-Liang Ma

Department of Emergency Medicine Faculty Papers

OBJECTIVE: Adiponectin (APN) system malfunction is causatively related to increased cardiovascular morbidity/mortality in diabetic patients. The aim of the current study was to investigate molecular mechanisms responsible for APN transmembrane signaling and cardioprotection.

METHODS AND RESULTS: Compared with wild-type mice, caveolin-3 knockout (Cav-3KO) mice exhibited modestly increased myocardial ischemia/reperfusion injury (increased infarct size, apoptosis, and poorer cardiac function recovery; P

CONCLUSIONS: Taken together, these results demonstrated for the first time that Cav-3 plays an essential role in APN transmembrane signaling and APN anti-ischemic/cardioprotective actions.

Macrophage Imbalance (M1 Vs. M2) And Upregulation Of Mast Cells In Wall Of Ruptured Human Cerebral Aneurysms: Preliminary Results., David Hasan, Nohra Chalouhi, Pascal Jabbour, Tomoki Hashimoto

Department of Neurosurgery Faculty Papers

BACKGROUND: M1 and M2 cells are two major subsets of human macrophages that exert opposite effects on the inflammatory response. This study aims to investigate the role of macrophage M1/M2 imbalance and mast cells in the progression of human cerebral aneurysms to rupture.

METHODS: Ten patients with cerebral aneurysms (five ruptured and five unruptured) underwent microsurgical clipping. During the procedure, a segment of the aneurysm dome was resected and immunostained with monoclonal antibodies for M1 cells (anti-HLA DR), M2 cells (anti-CD 163), and mast cells (anti-tryptase clone AA). A segment of the superficial temporal artery (STA) was also removed and …