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1.
Can J Hosp Pharm ; 77(2): e3543, 2024.
Article in English | MEDLINE | ID: mdl-38720917

ABSTRACT

Background: In older adults, the use of antipsychotics to treat delirium or the behavioural and psychological symptoms of dementia is potentially inappropriate and may be associated with adverse effects. Antipsychotics newly initiated in hospital may be inadvertently continued after discharge. In the Saskatchewan Health Authority (SHA) - Regina area, the frequency and duration of antipsychotic continuation for older adults after initiation during a hospital stay is unknown. Objectives: To describe potentially inappropriate antipsychotic use in older adults after discharge from hospital, specifically rates of postdischarge antipsychotic therapy after initiation in hospital and continuation up to 180 days after discharge; prescribing regimens used; risk factors associated with continuation; pharmacist involvement; and plans for antipsychotic discontinuation, tapering, and/or follow-up. Methods: This retrospective chart review included inpatients 65 years of age or older who were discharged from medicine units at SHA - Regina area hospitals between September 30, 2021, and June 28, 2022. Outpatient dispensing histories were also gathered. Results: Of the 189 patients included in the analysis, 60 (31.7%) had continuation of antipsychotic therapy at discharge. Of these, 48 (80.0%), 33 (55.0%), and 24 (40.0%) had continuation of antipsychotic therapy at 30, 90, and 180 days after discharge, respectively. Of the patients with continuing antipsychotic therapy, 53 (88.3%) were 75 years of age or older, and 9 (15.0%) had documentation of an outpatient antipsychotic follow-up plan. Conclusions: Postdischarge continuation of antipsychotics was similar to that reported in the literature. Patients continued on antipsychotics after discharge were at a greater than 50% risk of continuation at 90 days and were unlikely to have a follow-up plan. Future quality improvement efforts should include standardized prioritization of medication reviews, documentation of indications, and regular reassessment of therapy.


Contexte: Chez les personnes âgées, l'utilisation d'antipsychotiques pour traiter le délire ou les symptômes comportementaux et psychologiques de la démence est potentiellement inappropriée et associée à des effets indésirables. Le traitement antipsychotique initié à l'hôpital pourrait se poursuivre par inadvertance après le congé. Dans la région de Regina de la Saskatchewan Health Authority (SHA), la fréquence et la durée du maintien d'antipsychotiques chez les personnes âgées après l'initiation au cours d'un séjour à l'hôpital sont inconnues. Objectifs: Décrire l'utilisation potentiellement inappropriée d'antipsychotiques chez les personnes âgées après le congé de l'hôpital, en particulier les taux de traitement antipsychotique initié à l'hôpital qui continue après le congé et son maintien jusqu'à 180 jours après le congé; les schémas de prescription utilisés; les facteurs de risque associés au maintien; l'implication du pharmacien; et les plans visant à arrêter, réduire progressivement et/ou à faire le suivi de la prise d'antipsychotiques. Méthodologie: Cet examen rétrospectif des dossiers comprenait des patients hospitalisés âgés d'au moins 65 ans qui étaient sortis des unités de médecine d'hôpitaux de la région de Regina de la SHA entre le 30 septembre 2021 et le 28 juin 2022. Les historiques de délivrance en ambulatoire ont également été recueillis. Résultats: Sur les 189 patients inclus dans l'analyse, 60 (31,7 %) ont continué leur traitement antipsychotique au moment du congé. Parmi eux, 48 (80,0 %), 33 (55,0 %) et 24 (40,0 %) continuaient leur traitement antipsychotique à 30, 90 et 180 jours après leur congé, respectivement. Parmi les patients recevant un traitement antipsychotique continu, 53 (88,3 %) étaient âgés d'au moins 75 ans et 9 (15,0 %) avaient un plan de suivi antipsychotique ambulatoire. Conclusions: Le maintien des antipsychotiques après le congé était similaire à celui rapporté dans la littérature. Les patients qui continuaient à prendre des antipsychotiques après leur congé couraient un risque supérieur à 50 % de continuer à 90 jours et étaient peu susceptibles de disposer d'un plan de suivi. Les futurs efforts d'amélioration de la qualité devraient comprendre une priorisation standardisée des examens des médicaments, la documentation des indications et une réévaluation régulière du traitement.

2.
bioRxiv ; 2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38712246

ABSTRACT

Cholesterol- and sphingolipid-enriched domains called lipid rafts are hypothesized to selectively coordinate protein complex assembly within the plasma membrane to regulate cellular functions. Desmosomes are mechanically resilient adhesive junctions that associate with lipid raft membrane domains, yet the mechanisms directing raft association of the desmosomal proteins, particularly the transmembrane desmosomal cadherins, are poorly understood. We identified the desmoglein-1 (DSG1) transmembrane domain (TMD) as a key determinant of desmoglein lipid raft association and designed a panel of DSG1 TMD variants to assess the contribution of TMD physicochemical properties (length, bulkiness, and palmitoylation) to DSG1 lipid raft association. Sucrose gradient fractionations revealed that TMD length and bulkiness, but not palmitoylation, govern DSG1 lipid raft association. Further, DSG1 raft association determines plakoglobin recruitment to raft domains. Super-resolution imaging and functional assays uncovered a strong relationship between the efficiency of DSG1 TMD lipid raft association and the formation of morphologically and functionally robust desmosomes. Lipid raft association regulated both desmosome assembly dynamics and DSG1 cell surface stability, indicating that DSG1 lipid raft association is required for both desmosome formation and maintenance. These studies identify the biophysical properties of desmoglein transmembrane domains as key determinants of lipid raft association and desmosome adhesive function.

3.
Molecules ; 29(5)2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38474577

ABSTRACT

While numerous Fabaceae seeds are a good nutritional source of high-quality protein, the use of some species is hampered by toxic effects caused by exposure to metabolites that accumulate in the seeds. One such species is the faba or broad bean (Vicia faba L.), which accumulates vicine and convicine. These two glycoalkaloids cause favism, the breakdown of red blood cells in persons with a glucose-6-phosphate dehydrogenase deficiency. Because this is the most common enzyme deficiency worldwide, faba bean breeding efforts have focused on developing cultivars with low levels of these alkaloids. Consequently, quantification methods have been developed; however, they quantify vicine and convicine only and not the derivatives of these compounds that potentially generate the same bio-active molecules. Based on the recognition of previously unknown (con)vicine-containing compounds, we screened the fragmentation spectra of LC-MS/MS data from five faba bean cultivars using the characteristic fragments generated by (con)vicine. This resulted in the recognition of more than a hundred derivatives, of which 89 were tentatively identified. (Con)vicine was mainly derivatized through the addition of sugars, hydroxycinnamic acids, and dicarboxylic acids, with a group of compounds composed of two (con)vicine residues linked by dicarboxyl fatty acids. In general, the abundance profiles of the different derivatives in the five cultivars mimicked that of vicine and convicine, but some showed a derivative-specific profile. The description of the (con)vicine diversity will impact the interpretation of future studies on the biosynthesis of (con)vicine, and the content in potentially bio-active alkaloids in faba beans may be higher than that represented by the quantification of vicine and convicine alone.


Subject(s)
Alkaloids , Fabaceae , Glucosides , Pyrimidinones , Uridine/analogs & derivatives , Vicia faba , Vicia faba/chemistry , Liquid Chromatography-Mass Spectrometry , Chromatography, Liquid , Tandem Mass Spectrometry , Plant Breeding
4.
Can J Hosp Pharm ; 76(3): 177-184, 2023.
Article in English | MEDLINE | ID: mdl-37409152

ABSTRACT

Background: There is a paucity of literature describing the incidence of burnout among Canadian pharmacy residents, despite evidence that pharmacy professionals are at high risk of burnout. Objectives: To characterize Canadian pharmacy residents experiencing high levels of burnout, as defined by the Maslach Burnout Inventory (MBI), to describe existing interventions that Canadian pharmacy residents perceive to be effective in managing burnout, and to describe opportunities for Canadian pharmacy residency programs in managing resident burnout. Methods: An online survey, consisting of 22 validated questions from the MBI and 19 nonvalidated questions developed by the investigators, was distributed by email to 558 Canadian pharmacy residents from the 2020/21, 2019/20, and 2018/19 residency years. Results: A total of 115 partial or complete survey responses were included in the analysis, and 107 respondents completed the MBI section of the survey. Of these, 62% (66/107) were at high risk of burnout according to at least 1 MBI subscale, with a slight majority of the entire sample being at high risk of burnout on the emotional exhaustion subscale (55/107 [51%]). The most common interventions offered to pharmacy residents to reduce or prevent burnout were mentorship programs, schedule changes, and promotion of self-organization. Current interventions reported to be the most useful were self-care workshops, discussion groups, and workload adjustment. Potential future interventions perceived to be most useful for reducing and preventing burnout were schedule changes and workload adjustment. Conclusions: More than half of Canadian pharmacy residents who responded to the survey were at high risk of burnout. Canadian pharmacy residency programs should consider implementing additional interventions to help reduce and prevent resident burnout.


Contexte: Il y a peu de documentation qui décrit l'incidence de l'épuisement professionnel chez les résidents en pharmacie canadiens, malgré les preuves de risques élevés auxquels les professionnels en pharmacie sont exposés. Objectifs: Décrire les résidents canadiens en pharmacie qui connaissent des niveaux élevés d'épuisement professionnel, tels que définis par l'inventaire d'épuisement mis au point par Maslach et Jackson [en anglais Maslach Burnout Inventory (MBI)]; décrire les interventions existantes que ces personnes perçoivent comme efficaces pour le gérer; et décrire les possibilités de gestion de l'épuisement professionnel dans les programmes canadiens de résidence en pharmacie. Méthodes: Une enquête en ligne comprenant 22 questions validées du MBI et 19 questions non validées, préparées par les enquêteurs, a été envoyée par courriel à 558 résidents canadiens en pharmacie des années de résidence 2020­2021, 2019­2020 et 2018­2019. Résultats: Au total, 115 réponses partielles ou complètes ont été incluses dans l'analyse, et 107 répondants ont rempli la section MBI de l'enquête. Parmi ces derniers, 62 % (66/107) présentaient un risque élevé d'épuisement professionnel selon au moins 1 sous-échelle du MBI, une légère majorité de l'ensemble de l'échantillon présentant un risque élevé d'épuisement professionnel sur la sous-échelle d'épuisement émotionnel (55/107 [51 %]). Les interventions les plus courantes offertes aux résidents en pharmacie pour réduire ou prévenir l'épuisement professionnel étaient les programmes de mentorat, les changements d'horaire et la promotion de l'auto-organisation. Les interventions actuelles signalées comme étant les plus utiles étaient les ateliers d'autosoins, les groupes de discussion et l'adaptation de la charge de travail. Les interventions futures potentielles perçues comme les plus utiles pour réduire et prévenir l'épuisement professionnel étaient les changements d'horaire et l'adaptation de la charge de travail. Conclusions: Plus de la moitié des résidents canadiens en pharmacie qui ont répondu à l'enquête présentaient un risque élevé d'épuisement professionnel. Les programmes canadiens de résidence en pharmacie devraient envisager de mettre en œuvre des interventions supplémentaires pour aider à le réduire et à le prévenir.

5.
J Invest Dermatol ; 142(2): 323-332.e8, 2022 02.
Article in English | MEDLINE | ID: mdl-34352264

ABSTRACT

Dominant and recessive mutations in the desmosomal cadherin, desmoglein (DSG) 1, cause the skin diseases palmoplantar keratoderma (PPK) and severe dermatitis, multiple allergies, and metabolic wasting (SAM) syndrome, respectively. In this study, we compare two dominant missense mutations in the DSG1 transmembrane domain (TMD), G557R and G562R, causing PPK (DSG1PPK-TMD) and SAM syndrome (DSG1SAM-TMD), respectively, to determine the differing pathomechanisms of these mutants. Expressing the DSG1TMD mutants in a DSG-null background, we use cellular and biochemical assays to reveal the differences in the mechanistic behavior of each mutant. Super-resolution microscopy and functional assays showed a failure by both mutants to assemble desmosomes due to reduced membrane trafficking and lipid raft targeting. DSG1SAM-TMD maintained normal expression levels and turnover relative to wildtype DSG1, but DSG1PPK-TMD lacked stability, leading to increased turnover through lysosomal and proteasomal pathways and reduced expression levels. These results differentiate the underlying pathomechanisms of these disorders, suggesting that DSG1SAM-TMD acts dominant negatively, whereas DSG1PPK-TMD is a loss-of-function mutation causing the milder PPK disease phenotype. These mutants portray the importance of the DSG TMD in desmosome function and suggest that a greater understanding of the desmosomal cadherin TMDs will further our understanding of the role that desmosomes play in epidermal pathophysiology.


Subject(s)
Desmoglein 1/genetics , Desmosomes/pathology , Epidermis/pathology , Keratoderma, Palmoplantar/genetics , Cell Adhesion/genetics , Cell Line, Tumor , Desmoglein 1/metabolism , Desmosomal Cadherins/metabolism , Desmosomes/metabolism , Epidermis/metabolism , Humans , Keratoderma, Palmoplantar/pathology , Loss of Function Mutation , Membrane Microdomains/metabolism , Mutation, Missense , Protein Domains/genetics , Protein Stability
6.
Biochim Biophys Acta Biomembr ; 1862(9): 183329, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32376221

ABSTRACT

Desmosomes are cadherin-based adhesion structures that mechanically couple the intermediate filament cytoskeleton of adjacent cells to confer mechanical stress resistance to tissues. We have recently described desmosomes as mesoscale lipid raft membrane domains that depend on raft dynamics for assembly, function, and disassembly. Lipid raft microdomains are regions of the plasma membrane enriched in sphingolipids and cholesterol. These domains participate in membrane domain heterogeneity, signaling and membrane trafficking. Cellular structures known to be dependent on raft dynamics include the post-synaptic density in neurons, the immunological synapse, and intercellular junctions, including desmosomes. In this review, we discuss the current state of the desmosome field and put forward new hypotheses for the role of lipid rafts in desmosome adhesion, signaling and epidermal homeostasis. Furthermore, we propose that differential lipid raft affinity of intercellular junction proteins is a central driving force in the organization of the epithelial apical junctional complex.


Subject(s)
Cholesterol/chemistry , Cytoskeleton/chemistry , Desmosomes/chemistry , Membrane Microdomains/chemistry , Cadherins/chemistry , Cadherins/genetics , Cell Adhesion/genetics , Cytoskeleton/ultrastructure , Desmosomes/genetics , Epidermis , Humans , Membrane Lipids/chemistry , Membrane Microdomains/genetics , Signal Transduction/genetics , Sphingolipids/chemistry , Sphingolipids/genetics
7.
J Forensic Sci ; 65(2): 544-549, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31990383

ABSTRACT

In 2007, the Bureau of Justice Statistics reported on 2004 data collected from the Census of Medical Examiner and Coroner Offices (CMEC). The CMEC was one of the first comprehensive reports on the state of the medicolegal death investigation system in the United States and included information on administration, expenditure, workload, specialized death investigations, records and evidence retention, and resources. However, the report did not include responses on questions that were related to toxicology such as specimen retention and type of testing. The purpose of this publication is to provide the community with toxicology laboratory-specific responses from nearly 2000 medical examiner and coroner (MEC) offices. Data obtained from a BJS CMEC public use dataset for any remaining information that was not reported in the 2007 BJS report were evaluated specific to the operation of toxicology laboratories within a MEC office or specific to toxicology testing. The CMEC includes information on average operating budget for MEC offices with internal or external toxicology services, budget for toxicology/microbiology services, respondents' routine uses of toxicology analysis, toxicology specimen retention time, average turnaround times, use of computerized information management systems, and participation in federal data collections. These historical data begin to address the present state of our nation's toxicology laboratories within the medicolegal death investigation system and their preparedness for the current drug overdose epidemic.


Subject(s)
Coroners and Medical Examiners/organization & administration , Forensic Toxicology/organization & administration , Laboratories/organization & administration , Datasets as Topic , Drug Overdose , Humans , United States
8.
Cell Rep ; 28(4): 909-922.e6, 2019 07 23.
Article in English | MEDLINE | ID: mdl-31340153

ABSTRACT

Pemphigus vulgaris (PV) is an autoimmune disease characterized by blistering sores on skin and mucosal membranes, caused by autoantibodies primarily targeting the cellular adhesion protein, desmoglein-3 (Dsg3). To better understand how Dsg3-specific autoantibodies develop and cause disease in humans, we performed a cross-sectional study of PV patients before and after treatment to track relevant cellular responses underlying disease pathogenesis, and we provide an in-depth analysis of two patients by generating a panel of mAbs from single Dsg3-specific memory B cells (MBCs). Additionally, we analyzed a paired sample from one patient collected 15-months prior to disease diagnosis. We find that Dsg3-specific MBCs have an activated phenotype and show signs of ongoing affinity maturation and clonal selection. Monoclonal antibodies (mAbs) with pathogenic activity primarily target epitopes in the extracellular domains EC1 and EC2 of Dsg3, though they can also bind to the EC4 domain. Combining antibodies targeting different epitopes synergistically enhances in vitro pathogenicity.


Subject(s)
Autoimmune Diseases/immunology , Pemphigus/immunology , Single-Cell Analysis , Antibodies, Monoclonal/immunology , Autoantigens/immunology , B-Lymphocytes/immunology , Desmoglein 3/chemistry , Desmoglein 3/immunology , Germ Cells/metabolism , Humans , Immunologic Memory , Protein Binding , Protein Domains , Somatic Hypermutation, Immunoglobulin/genetics
10.
Mol Biol Cell ; 30(12): 1390-1405, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30943110

ABSTRACT

Desmogleins (Dsgs) are cadherin family adhesion molecules essential for epidermal integrity. Previous studies have shown that desmogleins associate with lipid rafts, but the significance of this association was not clear. Here, we report that the desmoglein transmembrane domain (TMD) is the primary determinant of raft association. Further, we identify a novel mutation in the DSG1 TMD (G562R) that causes severe dermatitis, multiple allergies, and metabolic wasting syndrome. Molecular modeling predicts that this G-to-R mutation shortens the DSG1 TMD, and experiments directly demonstrate that this mutation compromises both lipid raft association and desmosome incorporation. Finally, cryo-electron tomography indicates that the lipid bilayer within the desmosome is ∼10% thicker than adjacent regions of the plasma membrane. These findings suggest that differences in bilayer thickness influence the organization of adhesion molecules within the epithelial plasma membrane, with cadherin TMDs recruited to the desmosome via the establishment of a specialized mesoscale lipid raft-like membrane domain.


Subject(s)
Desmosomes/metabolism , Membrane Microdomains/metabolism , Amino Acid Sequence , Animals , Desmogleins/chemistry , Desmogleins/metabolism , Humans , Lipid Bilayers/metabolism , Lipoylation , Mice , Models, Biological , Mutation/genetics , Protein Domains
11.
Cell Rep ; 20(1): 1-12, 2017 07 05.
Article in English | MEDLINE | ID: mdl-28683304

ABSTRACT

Genomic studies have repeatedly associated variants in the gene encoding the microRNA miR-137 with increased schizophrenia risk. Bioinformatic predictions suggest that miR-137 regulates schizophrenia-associated signaling pathways critical to neural development, but these predictions remain largely unvalidated. In the present study, we demonstrate that miR-137 regulates neuronal levels of p55γ, PTEN, Akt2, GSK3ß, mTOR, and rictor. All are key proteins within the PI3K-Akt-mTOR pathway and act downstream of neuregulin (Nrg)/ErbB and BDNF signaling. Inhibition of miR-137 ablates Nrg1α-induced increases in dendritic protein synthesis, phosphorylated S6, AMPA receptor subunits, and outgrowth. Inhibition of miR-137 also blocks mTORC1-dependent responses to BDNF, including increased mRNA translation and dendritic outgrowth, while leaving mTORC1-independent S6 phosphorylation intact. We conclude that miR-137 regulates neuronal responses to Nrg1α and BDNF through convergent mechanisms, which might contribute to schizophrenia risk by altering neural development.


Subject(s)
MicroRNAs/genetics , Neuregulin-1/metabolism , Neurogenesis , Schizophrenia/genetics , Signal Transduction , Animals , Brain-Derived Neurotrophic Factor/metabolism , Cell Line, Tumor , Cells, Cultured , Glycogen Synthase Kinase 3 beta/genetics , Glycogen Synthase Kinase 3 beta/metabolism , Mechanistic Target of Rapamycin Complex 1/genetics , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice , Mice, Inbred C57BL , MicroRNAs/metabolism , Neurons/cytology , Neurons/metabolism , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Rapamycin-Insensitive Companion of mTOR Protein/genetics , Rapamycin-Insensitive Companion of mTOR Protein/metabolism
12.
Dev Neurobiol ; 77(6): 738-752, 2017 06.
Article in English | MEDLINE | ID: mdl-27643955

ABSTRACT

The autism-related protein Fragile X mental retardation protein (FMRP) is an RNA binding protein that plays important roles during both nervous system development and experience dependent plasticity. Alternative splicing of the Fmr1 locus gives rise to 12 different FMRP splice forms that differ in the functional and regulatory domains they contain as well as in their expression profile among brain regions and across development. Complete loss of FMRP leads to morphological and functional changes in neurons, including an increase in the size and complexity of the axonal arbor. To investigate the relative contribution of the FMRP splice forms to the regulation of axon morphology, we overexpressed individual splice forms in cultured wild type rat cortical neurons. FMRP overexpression led to a decrease in axonal arbor complexity that suggests that FMRP regulates axon branching. This reduction in complexity was specific to three splice forms-the full-length splice form 1, the most highly expressed splice form 7, and splice form 9. A focused analysis of splice form 7 revealed that this regulation is independent of RNA binding. Instead this regulation is disrupted by mutations affecting phosphorylation of a conserved serine as well as by mutating the nuclear export sequence. Surprisingly, this mutation in the nuclear export sequence also led to increased localization to the distal axonal arbor. Together, these findings reveal domain-specific functions of FMRP in the regulation of axonal complexity that may be controlled by differential expression of FMRP splice forms. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 738-752, 2017.


Subject(s)
Alternative Splicing/genetics , Axons/physiology , Fragile X Mental Retardation Protein/genetics , Fragile X Mental Retardation Protein/metabolism , Neurons/cytology , Analysis of Variance , Animals , Cells, Cultured , Cerebral Cortex/cytology , Embryo, Mammalian , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Humans , Mutation/genetics , Protein Isoforms/genetics , Protein Isoforms/metabolism , Rats , Transfection
13.
Bone ; 50(1): 42-53, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21958845

ABSTRACT

CSF-1, a key regulator of mononuclear phagocyte production, is highly expressed in the skeleton by osteoblasts/osteocytes and in a number of nonskeletal tissues such as uterus, kidney and brain. The spontaneous mutant op/op mouse has been the conventional model of CSF-1 deficiency and exhibits a pleiotropic phenotype characterized by osteopetrosis, and defects in hematopoiesis, fertility and neural function. Studies to further delineate the biologic effect of CSF-1 within various tissues have been hampered by the lack of suitable models. To address this issue, we generated CSF-1 floxed/floxed mice and demonstrate that Cre-mediated recombination using Meox2Cre, a Cre line expressed in epiblast during early embryogenesis, results in mice with ubiquitous CSF-1 deficiency (CSF-1KO). Homozygous CSF-1KO mice lacked CSF-1 in all tissues and displayed, in part, a similar phenotype to op/op mice that included: failure of tooth eruption, osteopetrosis, reduced macrophage densities in reproductive and other organs and altered hematopoiesis with decreased marrow cellularity, circulating monocytes and B cell lymphopoiesis. In contrast to op/op mice, CSF-1KO mice showed elevated circulating and splenic T cells. A striking feature in CSF-1KO mice was defective osteocyte maturation, bone mineralization and osteocyte-lacunar system that was associated with reduced dentin matrix protein 1 (DMP1) expression in osteocytes. CSF-1KO mice also showed a dramatic reduction in osteomacs along the endosteal surface that may have contributed to the hematopoietic and cortical bone defects. Thus, our findings show that ubiquitous CSF-1 gene deletion using a Cre-based system recapitulates the expected osteopetrotic phenotype. Moreover, results point to a novel link between CSF-1 and osteocyte survival/function that is essential for maintaining bone mass and strength during skeletal development.


Subject(s)
Homeodomain Proteins/metabolism , Integrases/metabolism , Macrophage Colony-Stimulating Factor/genetics , Macrophage Colony-Stimulating Factor/metabolism , Osteocytes/pathology , Osteopetrosis/pathology , Animals , Bone and Bones/abnormalities , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Bone and Bones/physiology , Gene Targeting , Homeodomain Proteins/genetics , Integrases/genetics , Macrophages/cytology , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Mutant Strains , Osteocytes/cytology , Osteopetrosis/physiopathology , Tooth/anatomy & histology , Tooth/pathology , Tooth/physiology , Tooth Eruption/genetics , X-Ray Microtomography
14.
Exp Hematol ; 40(4): 295-306.e5, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22198154

ABSTRACT

Myelodysplastic syndrome is a complex family of preleukemic diseases in which hematopoietic stem cell defects lead to abnormal differentiation in one or more blood lineages. Disease progression is associated with increasing genomic instability and a large proportion of patients go on to develop acute myeloid leukemia. Primarily a disease of the elderly, it can also develop after chemotherapy. We have previously reported that CREB binding protein (Crebbp) heterozygous mice have an increased incidence of hematological malignancies, and others have shown that CREBBP is one of the genes altered by chromosomal translocations found in patients suffering from therapy-related myelodysplastic syndrome. This led us to investigate whether hematopoietic tumor development in Crebbp(+/-) mice is preceded by a myelodysplastic phase and whether we could uncover molecular mechanisms that might contribute to its development. We report here that Crebbp(+/-) mice invariably develop myelodysplastic/myeloproliferative neoplasm within 9 to 12 months of age. They are also hypersensitive to ionizing radiation and show a marked decrease in poly(ADP-ribose) polymerase-1 activity after irradiation. In addition, protein levels of XRCC1 and APEX1, key components of base excision repair machinery, are reduced in unirradiated Crebbp(+/-) cells or upon targeted knockdown of CREBBP levels. Our results provide validation of a novel myelodysplastic/myeloproliferative neoplasm mouse model and, more importantly, point to defective repair of DNA damage as a contributing factor to the pathogenesis of this currently incurable disease.


Subject(s)
CREB-Binding Protein/genetics , DNA Repair/genetics , Gamma Rays/adverse effects , Myelodysplastic Syndromes/genetics , Myeloproliferative Disorders/genetics , Radiation Tolerance/genetics , Animals , CREB-Binding Protein/physiology , DNA Damage , Disease Progression , Gene Expression Regulation , Gene Knockdown Techniques , Gene Regulatory Networks , Genomic Instability , Heterozygote , Mice , Mice, Inbred C57BL , Preleukemia/genetics , RNA, Small Interfering/genetics , RNA, Small Interfering/toxicity , Whole-Body Irradiation/adverse effects
15.
Blood ; 118(1): 69-79, 2011 Jul 07.
Article in English | MEDLINE | ID: mdl-21555743

ABSTRACT

CREB-binding protein (CREBBP) is important for the cell-autonomous regulation of hematopoiesis, including the stem cell compartment. In the present study, we show that CREBBP plays an equally pivotal role in microenvironment-mediated regulation of hematopoiesis. We found that the BM microenvironment of Crebbp(+/-) mice was unable to properly maintain the immature stem cell and progenitor cell pools. Instead, it stimulates myeloid differentiation, which progresses into a myeloproliferation phenotype. Alterations in the BM microenvironment resulting from haploinsufficiency of Crebbp included a marked decrease in trabecular bone that was predominantly caused by increased osteoclastogenesis. Although CFU-fibroblast (CFU-F) and total osteoblast numbers were decreased, the bone formation rate was similar to that found in wild-type mice. At the molecular level, we found that the known hematopoietic modulators matrix metallopeptidase-9 (MMP9) and kit ligand (KITL) were decreased with heterozygous levels of Crebbp. Lastly, potentially important regulatory proteins, endothelial cell adhesion molecule 1 (ESAM1) and cadherin 5 (CDH5), were increased on Crebbp(+/-) endothelial cells. Our findings reveal that a full dose of Crebbp is essential in the BM microenvironment to maintain proper hematopoiesis and to prevent excessive myeloproliferation.


Subject(s)
Bone Marrow/physiology , CREB-Binding Protein/genetics , Haploinsufficiency/physiology , Hematopoietic Stem Cells/physiology , Myelopoiesis/physiology , Animals , CREB-Binding Protein/immunology , CREB-Binding Protein/metabolism , Cell Differentiation/physiology , Cell Line , E1A-Associated p300 Protein/genetics , E1A-Associated p300 Protein/immunology , E1A-Associated p300 Protein/metabolism , Endothelial Cells/cytology , Endothelial Cells/physiology , Female , Femur/cytology , Femur/physiology , Hematopoietic Stem Cells/cytology , Heterozygote , Male , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Osteoclasts/cytology , Osteoclasts/physiology , Stem Cell Factor/metabolism , Stromal Cells/cytology , Stromal Cells/physiology
16.
J Obstet Gynecol Neonatal Nurs ; 39(2): 212-9, 2010.
Article in English | MEDLINE | ID: mdl-20409123

ABSTRACT

This article describes the collaborative efforts of a parish nurse, family nurse practitioner, and a registered dietitian in a faith-based setting to address the women's health issue of osteoporosis. A model for education and treatment including lifestyle changes, nutrition, and pharmacological therapies is discussed. The whole person perspective of prevention and management for women with this chronic disease is explored. Implications for practice and education for women across the life span are described.


Subject(s)
Community Health Nursing/organization & administration , Dietetics/organization & administration , Nurse Practitioners/organization & administration , Osteoporosis, Postmenopausal/prevention & control , Pastoral Care , Specialties, Nursing/organization & administration , Accidental Falls/prevention & control , Cooperative Behavior , Family Nursing/organization & administration , Feeding Behavior , Female , Health Education/organization & administration , Humans , Life Style , Models, Educational , Models, Nursing , Nurse's Role , Osteoporosis, Postmenopausal/etiology , Pastoral Care/organization & administration , Program Development , Risk Factors , Spirituality , Women's Health
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