Gary Weisman - Profile on Academia.edu (original) (raw)

Papers by Gary Weisman

American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2019

Head and neck cancer treatments typically involve a combination of surgery and radiotherapy, ofte... more Head and neck cancer treatments typically involve a combination of surgery and radiotherapy, often leading to collateral damage to nearby tissues causing unwanted side effects. Radiation damage to salivary glands frequently leads to irreversible dysfunction by poorly understood mechanisms. The P2X7 receptor (P2X7R) is a ligand-gated ion channel activated by extracellular ATP released from damaged cells as “danger signals.” P2X7R activation initiates apoptosis and is involved in numerous inflammatory disorders. In this study, we utilized P2X7R knockout (P2X7R−/−) mice to determine the role of the receptor in radiation-induced salivary gland damage. Results indicate a dose-dependent increase in γ-radiation-induced ATP release from primary parotid gland cells of wild-type but not P2X7R−/− mice. Despite these differences, apoptosis levels are similar in parotid glands of wild-type and P2X7R−/− mice 24–72 h after radiation. However, γ-radiation caused elevated prostaglandin E2 (PGE2) rel...

BzATP or ATP induces ERK1/2 and JNK1 phosphorylation in rPCNs

<b>Copyright information:</b>Taken from "P2X nucleotide receptors mediate caspas... more <b>Copyright information:</b>Taken from "P2X nucleotide receptors mediate caspase-8/9/3-dependent apoptosis in rat primary cortical neurons"Purinergic Signalling 2005;1(4):337-347.Published online Jan 2005PMCID:PMC2096553. Rat PCNs were incubated in serum-free HGGMEM for 6 h and treated with the indicated concentration (µM) of BzATP or ATP for 5 min or with 100 µM ATP or 300 µM BzATP for the indicated time period. Cells cultured in serum-free HGGMEM (−) overnight were used as the control. Then, cell lysates were prepared and (A) ERK1/2 or (B) JNK1 phosphorylation was detected by Western analysis, as described in the Materials and methods. Total ERK1/2 and actin were used as protein loading controls for (A) and (B), respectively.

Purinergic Signalling, Feb 28, 2007

Atherosclerosis is an immunoinflammatory process that involves complex interactions between the v... more Atherosclerosis is an immunoinflammatory process that involves complex interactions between the vessel wall and blood components and is thought to be initiated by endothelial dysfunction [

Frontiers in Bioengineering and Biotechnology, Jul 21, 2021

Annually, >600,000 new cases of head and neck cancer (HNC) are diagnosed worldwide with primary t... more Annually, >600,000 new cases of head and neck cancer (HNC) are diagnosed worldwide with primary treatment being surgery and radiotherapy. During ionizing radiation (IR) treatment of HNC, healthy salivary glands are collaterally damaged, leading to loss of function that severely diminishes the quality of life for patients due to increased health complications, including oral infections and sores, cavities, and malnutrition, among others. Therapies for salivary hypofunction are ineffective and largely palliative, indicating a need for further research to uncover effective approaches to prevent or restore loss of salivary gland function following radiotherapy. Previous work in our lab implicated prostaglandin E 2 (PGE 2) as an inflammatory mediator whose release from radiation-exposed cells promotes salivary gland damage and loss of function. Deletion of the P2X7 purinergic receptor for extracellular ATP reduces PGE 2 secretion in irradiated primary parotid gland cells, and salivary gland function is enhanced in irradiated P2X7R −/− mice compared to wild-type mice. However, the role of PGE 2 signaling in irradiated salivary glands is unclear and understanding the mechanism of PGE 2 action is a goal of this study. Results show that treatment of irradiated mice with the non-steroidal anti-inflammatory drug (NSAID) indomethacin, which reduces PGE 2 production via inhibition of cyclooxygenase-1 (COX-1), improves salivary gland function compared to irradiated vehicle-treated mice. To define the signaling pathway whereby PGE 2 induces salivary gland dysfunction, primary parotid gland cells treated with PGE 2 have increased c-Jun N-terminal Kinase (JNK) activation and cell proliferation and reduced amylase levels and store-operated calcium entry (SOCE). The in vivo effects of blocking PGE 2 production were also examined and irradiated mice receiving indomethacin injections have reduced JNK activity at 8 days post-irradiation and reduced proliferation and increased amylase levels at day 30, as compared to irradiated mice without indomethacin. Combined, these data suggest a mechanism whereby irradiation-induced PGE 2 signaling to JNK blocks critical steps in saliva secretion

Therapeutic potential for P2Y2 receptor antagonism

Purinergic Signalling

Early Dry Eye Disease Onset in a NOD.H-2h4 Mouse Model of Sjögren's Syndrome

Investigative Opthalmology & Visual Science

Molecular mechanisms of endothelium-dependent vasodilation via P2Y nucleotide receptors

Journal of Molecular and Cellular Cardiology, 1998

Evolution, correlation, structural impact and dynamics of emerging SARS-CoV-2 variants

Computational and Structural Biotechnology Journal, 2021

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infections remain unmanageable in so... more Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infections remain unmanageable in some parts of the world. As with other RNA viruses, mutations in the SARS-CoV-2 gene have been continuously evolving. Recently, four variants have been identified, B.1.1.7, B.1.351, P.1 and CAL.20C. These variants appear to be more infectious and transmissible than the original Wuhan-Hu-1 virus. Using a combination of bioinformatics and structural analyses, we show that the new SARS-CoV-2 variants emerged in the background of an already known Spike protein mutation D614G together with another mutation P323L in the RNA polymerase of SARS-CoV-2. The phylogenetic analysis showed that the CAL.20C and B.1.351 shared one common ancestor, whereas the B.1.1.7 and P.1 shared a different ancestor. Structural comparisons did not show any significant difference between the wild-type and mutant ACE2/Spike complexes. Structural analysis indicated that the N501Y mutation may increase hydrophobic interactions at the ACE2/Spike interface. However, reported greater binding affinity of N501Y Spike with ACE2 does not seem to be entirely due to increased hydrophobic interactions, given that Spike mutation R417T in P.1 or K417N in B.1.351 results in the loss of a salt-bridge interaction between ACE2 and S-RBD. The calculated change in free energy did not provide a clear trend of S protein stability of mutations in the variants. As expected, we show that the CAL.20C generally migrated from the west coast to the east coast of the USA. Taken together, the analyses suggest that the evolution of variants and their infectivity is complex and may depend upon many factors.

ImmunoHorizons, 2018

CD40/CD40L interactions play a critical role in immunity and autoimmunity. In this study, we soug... more CD40/CD40L interactions play a critical role in immunity and autoimmunity. In this study, we sought to understand the requirement for CD40 signaling in the programmed cell death-1 (PD-1) checkpoint and CD28 costimulatory pathways important for maintenance of peripheral tolerance. Blocking either pathway can result in loss of self-tolerance and development of autoimmunity. We found that primary Sjögren’s syndrome (pSS) and autoimmune thyroid diseases (ATDs) that develop spontaneously in CD28-deficient IFN-γ−/− NOD.H-2h4 (CD28−/−) mice required CD40 signaling. Specifically, blockade of CD40L with the anti-CD40L mAb, MR1, inhibited autoantibody production and inflammation in thyroid and salivary gland target tissues. Unexpectedly, however, ATD and pSS in PD-1–deficient IFN-γ−/− NOD.H-2h4 (PD-1−/−) mice developed independently of CD40/CD40L interactions. Treatment with MR1 had no effect and even exacerbated disease development in pSS and ATD, respectively. Most interesting, anti-thyrogl...

Purinergic Signalling, 2015

Journal of Biological Chemistry, 1998

Molecular determinants of P2Y 2 receptor desensitization and sequestration have been investigated... more Molecular determinants of P2Y 2 receptor desensitization and sequestration have been investigated. Wildtype P2Y 2 receptors and a series of five C-terminal truncation mutants of the receptor were epitope-tagged and stably expressed in 1321N1 cells. These constructs were used to assess the importance of the intracellular C terminus on 1) UTP-stimulated increases in intracellular calcium concentration, 2) homologous desensitization of the receptor, and 3) agonist-induced decreases in cellsurface density (receptor sequestration) of epitopetagged receptors using fluorescence-activated cell sorting. The potency and efficacy of UTP were similar for the wild-type and all mutant P2Y 2 receptors. Truncation of 18 or more amino acids from the C terminus increased by ϳ30-fold the concentration of UTP necessary to desensitize the receptor. Both the rate and magnitude of UTP-induced receptor sequestration were decreased with progressively larger truncations of the C terminus. Furthermore, the recovery from sequestration was slower for the most extensively truncated receptor. Complete desensitization was obtained with >50% of the original receptor complement remaining on the cell surface. Protein kinase C activation, which desensitizes the P2Y 2 receptor, had no effect on sequestration, consistent with the ideas that desensitization and sequestration are discrete events and that agonist occupancy is required for receptor sequestration.

Atherosclerosis, 2016

Background and aims-The internalization of aggregated low-density lipoproteins (agLDL) mediated b... more Background and aims-The internalization of aggregated low-density lipoproteins (agLDL) mediated by low-density lipoprotein receptor related protein (LRP1) may involve the actin cytoskeleton in ways that differ from the endocytosis of soluble LDL by the LDL receptor (LDLR). This study aims to define novel mechanisms of agLDL uptake through modulation of the actin cytoskeleton, to identify molecular targets involved in foam cell formation in vascular smooth muscle cells (VSMCs). The critical observation that formed the basis for these studies is that under pathophysiological conditions, nucleotide release from blood-derived and vascular cells activates SMC P2Y 2 receptors (P2Y 2 Rs) leading to rearrangement of the actin cytoskeleton and cell motility. Therefore, we tested the hypothesis that P2Y 2 R activation mediates agLDL uptake by VSMCs. VSMCs were isolated from aortas of wild type (WT) C57BL/6 and.P2Y2R-/ -mice to investigate whether P2Y 2 R activation modulates LRP1 expression. Cells were transiently transfected with cDNA encoding a hemagglutinin-tagged (HA-tagged) WT P2Y 2 R, or a mutant P2Y 2 R that unlike the WT P2Y 2 R does not bind the cytoskeletal actin-binding protein filamin-A (FLN-A). Results-P2Y 2 R activation significantly increased agLDL uptake, and LRP1 mRNA expression decreased in P2Y2R-/-VSMCs versus WT. SMCs, expressing P2Y 2 R defective in FLN-A binding, exhibit 3-fold lower LDLR expression levels than SMCs expressing WT P2Y 2 R, while

The P2Y2 receptor regulates lipoprotein receptor‐related protein 1 expression in smooth muscle cells

The FASEB Journal

Extracellular nucleotides exert various effects in the cardiovascular system. Uridine 5′‐triphosp... more Extracellular nucleotides exert various effects in the cardiovascular system. Uridine 5′‐triphosphate (UTP) regulates G‐protein‐coupled P2Y2 receptor (P2Y2R) activation which causes actin cytoskeletal reorganization. We isolated aortic smooth muscle cells (SMC) from wild‐type (WT) and P2Y2R−/− mice to investigate whether UTP and the P2Y2R modulate expression of low density lipoprotein receptor‐related protein 1 (LRP1) and low density lipoprotein receptor (LDLR). For LRP1 expression, cells were stimulated in the presence or absence of 100 μM UTP overnight. For LDLR mRNA expression, cells were transiently transfected for 24 h with cDNA encoding a hemagglutinin‐tagged WT P2Y2R or a mutant P2Y2R that does not bind filamin‐A (FLN‐A) and treated with 100 μM UTP overnight. Total RNA was isolated, reversed transcribed to cDNA, and mRNA abundance determined by RT‐PCR using the ΔCt method with GAPDH as a control gene. Results show SMC expressing the P2Y2R that lacks the FLN‐A binding domain e...

Research Article Endocytosis mechanism of P2Y 2 nucleotide receptor tagged with green fluorescent protein: clathrin and actin cytoskeleton dependence

Extracellular nucleotides exert a large num- ber of physiological effects through activation of P... more Extracellular nucleotides exert a large num- ber of physiological effects through activation of P2Y re- ceptors. We expressed rat P2Y2 (rP2Y2) receptor, tagged with green fluorescent protein (GFP) in HEK-293 cells and visualized receptor translocation in live cells by confocal microscopy. Functional receptor expression was confirmed by determining (Ca 2+ )i responses. Agonist stimulation caused a time-dependent translocation of the receptor from the plasma membrane to the cytoplasm. Rearrangement of the actin cytoskeleton was observed during agonist-mediated rP2Y2-GFP receptor internal-

IUPHAR/BPS guide to pharmacology CITE, Sep 16, 2019

P2Y receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2Y Receptors [3, 5]) are ... more P2Y receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2Y Receptors [3, 5]) are activated by the endogenous ligands ATP, ADP, uridine triphosphate, uridine diphosphate and UDP-glucose. The relationship of many of the cloned receptors to endogenously expressed receptors is not yet established and so it might be appropriate to use wording such as 'uridine triphosphate-preferring (or ATP-, etc.) P2Y receptor' or 'P2Y 1-like', etc., until further, as yet undefined, corroborative criteria can be applied [46, 109, 187, 375, 388]. Clinically used drugs acting on these receptors include the dinucleoside polyphosphate diquafosol, agonist of the P2Y 2 receptor subtype, approved in Japan for the management of dry eye disease [ 236], and the P2Y 12 receptor antagonists prasugrel, ticagrelor and cangrelor, all approved as antiplatelet drugs [ 52, 316]. Contents This is a citation summary for P2Y receptors in the Guide to Pharmacology database (GtoPdb). It exists purely as an adjunct to the database to facilitate the recognition of citations to and from the database by citation analyzers. Readers will almost certainly want to visit the relevant sections of the database which are given here under database links. GtoPdb is an expert-driven guide to pharmacological targets and the substances that act on them. GtoPdb is a reference work which is most usefully represented as an on-line database. As in any publication this work should be appropriately cited, and the papers it cites should also be recognized. This document provides a citation for the relevant parts of the database, and also provides a reference list for the research cited by those parts. Please note that the database version for the citations given in GtoPdb are to the most recent preceding version in which the family or its subfamilies and targets were substantially changed. The links below are to the current version. If you need to consult the cited version, rather than the most recent version, please contact the GtoPdb curators.

IUPHAR/BPS guide to pharmacology CITE, Apr 26, 2023

P2Y receptors (nomenclature as agreed by the nomenclature as agreed by the NC-IUPHAR NC-IUPHAR Su... more P2Y receptors (nomenclature as agreed by the nomenclature as agreed by the NC-IUPHAR NC-IUPHAR Subcommittee on P2Y Receptors [ Subcommittee on P2Y Receptors [3 3, , 5 5, , 189 189] ]) are activated by the endogenous ligands ATP, ADP, UTP, UDP, UDP-glucose and adenosine. The eight mammalian P2Y receptors are activated by distinct nucleotides: P2Y 1 , P2Y 11 , P2Y 12 and P2Y 13 are activated by adenosine-nucleotides; P2Y 2 , P2Y 4 can be activated by both adenosine and uridine nucleotides, with some species-specific differences; P2Y 6 is mainly activated by UDP; P2Y 14 is preferentially activated by sugaruracil nucleotides. The missing numbers in the receptor nomenclature refer either to non-mammalian orthologs or receptors having some sequence homology to P2Y receptors but for which there is no functional evidence of responsiveness to nucleotides [380]. Based on their G protein coupling P2Y receptors can be divided into two subfamilies: P2Y 1 , P2Y 2 , P2Y 4 , P2Y 6 and P2Y 11 receptors couple via Gq proteins to stimulate phospholipase C followed by increases in inositol phosphates and mobilization of Ca 2+ from intracellular stores. P2Y 11 receptors couple in addition to Gs proteins followed by increased adenylate cyclase activity. In contrast, P2Y 12 , P2Y 13 , and P2Y 14 receptors signal primarily through activation of Gi proteins and inhibition of adenylate cyclase activity or control of ion channel activity [380]. Clinically used drugs acting on these receptors include the dinucleoside polyphosphate diquafosol, agonist of the P2Y 2 receptor subtype, approved in Japan and South Korea for the management of dry eye disease [238], and the P2Y 12 receptor antagonists prasugrel, ticagrelor and cangrelor, all approved as antiplatelet drugs [52, 320]. Contents Contents This is a citation summary for P2Y receptors in the Guide to Pharmacology database (GtoPdb). It exists purely as an adjunct to the database to facilitate the recognition of citations to and from the database by citation analyzers. Readers will almost certainly want to visit the relevant sections of the database which are given here under database links. GtoPdb is an expert-driven guide to pharmacological targets and the substances that act on them. GtoPdb is a reference work which is most usefully represented as an on-line database. As in any publication this work should be appropriately cited, and the papers it cites should also be recognized. This document provides a citation for the relevant parts of the database, and also provides a reference list for the research cited by those parts. For further details see [44]. Please note that the database version for the citations given in GtoPdb are to the most recent preceding version in which the family or its subfamilies and targets were substantially changed. The links below are to the current version.

IUPHAR/BPS guide to pharmacology CITE, Sep 2, 2021

P2Y receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2Y Receptors [3, 5, 192])... more P2Y receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2Y Receptors [3, 5, 192]) are activated by the endogenous ligands ATP, ADP, uridine triphosphate, uridine diphosphate and UDP-glucose. The relationship of many of the cloned receptors to endogenously expressed receptors is not yet established and so it might be appropriate to use wording such as 'uridine triphosphate-preferring (or ATP-, etc.) P2Y receptor' or 'P2Y 1-like', etc., until further, as yet undefined, corroborative criteria can be applied [47, 110, 190, 383, 396]. Clinically used drugs acting on these receptors include the dinucleoside polyphosphate diquafosol, agonist of the P2Y 2 receptor subtype, approved in Japan for the management of dry eye disease [241], and the P2Y 12 receptor antagonists prasugrel, ticagrelor and cangrelor, all approved as antiplatelet drugs [53, 323]. Contents This is a citation summary for P2Y receptors in the Guide to Pharmacology database (GtoPdb). It exists purely as an adjunct to the database to facilitate the recognition of citations to and from the database by citation analyzers. Readers will almost certainly want to visit the relevant sections of the database which are given here under database links. GtoPdb is an expert-driven guide to pharmacological targets and the substances that act on them. GtoPdb is a reference work which is most usefully represented as an on-line database. As in any publication this work should be appropriately cited, and the papers it cites should also be recognized. This document provides a citation for the relevant parts of the database, and also provides a reference list for the research cited by those parts. For further details see [44]. Please note that the database version for the citations given in GtoPdb are to the most recent preceding version in which the family or its subfamilies and targets were substantially changed. The links below are to the current version. If you need to consult the cited version, rather than the most recent version, please contact the GtoPdb curators.

Interaction Between the P2Y2 Nucleotide Receptor and Filamin A Regulates Cell Motility

The FASEB Journal, 2006

Focal Adhesion Kinase Mediates Nucleotide P2Y 2 Receptor‐Dependent Increased Endothelial Permeability

The FASEB Journal, Apr 1, 2015