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1.
Cell Rep ; 24(4): 1037-1049, 2018 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-30044971

RESUMEN

Mammalian sphingolipids, primarily with C24 or C16 acyl chains, reside in the outer leaflet of the plasma membrane. Curiously, little is known how C24 sphingolipids impact cholesterol and membrane microdomains. Here, we present evidence that C24 sphingomyelin, when placed in the outer leaflet, suppresses microdomains in giant unilamellar vesicles and also suppresses submicron domains in the plasma membrane of HeLa cells. Free energy calculations suggested that cholesterol has a preference for the inner leaflet if C24 sphingomyelin is in the outer leaflet. We indeed observe that cholesterol enriches in the inner leaflet (80%) if C24 sphingomyelin is in the outer leaflet. Similarly, cholesterol primarily resides in the cytoplasmic leaflet (80%) in the plasma membrane of human erythrocytes where C24 sphingolipids are naturally abundant in the outer leaflet. We conclude that C24 sphingomyelin uniquely interacts with cholesterol and regulates the lateral organization in asymmetric membranes, potentially by generating cholesterol asymmetry.


Asunto(s)
Colesterol/metabolismo , Esfingolípidos/metabolismo , Membrana Celular/metabolismo , Colesterol/sangre , Membrana Eritrocítica/metabolismo , Eritrocitos/metabolismo , Transferencia Resonante de Energía de Fluorescencia , Células HeLa , Humanos , Membrana Dobles de Lípidos , Microdominios de Membrana/metabolismo , Esfingolípidos/sangre
2.
Int J Obes (Lond) ; 33 Suppl 4: S21-8, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19623184

RESUMEN

HEALTHY was a 3-year middle school-based primary prevention trial to reduce modifiable risk factors for type 2 diabetes in youth. The study was conducted at seven centers across the country. This paper describes the recruitment and retention activities employed in the study. Schools and students were the focus of recruitment and retention. Each center was responsible for the recruitment of six schools; eligibility was based on ability to enroll a sufficient number of predominately minority and lower socioeconomic status students. Study staff met with district superintendents and school principals to verify the eligibility of schools, and to ascertain how appropriate the school would be for conducting the trial. Sixth grade students were recruited employing a variety of techniques; students and their parents did not know whether their school was randomized to the intervention or control arm. This cohort was followed through sixth, seventh and eighth grades. In the eighth grade, an additional sample of students who were not originally enrolled in the study was recruited in a similar manner to participate in data collection to allow for cross-sectional and dose-response secondary analyses. Parents signed informed consent forms and children signed informed assent forms, as per the needs of the local Institutional Review Board. Parents received a letter describing the results of the health screening for their children after data collection in sixth and eighth grades. Retention of schools and students was critical for the success of the study and was encouraged through the use of financial incentives and other strategies. To a large extent, student withdrawal due to out-migration (transfer and geographical relocation) was beyond the ability of the study to control. A multi-level approach that proactively addressed school and parent concerns was crucial for the success of recruitment and retention in the HEALTHY study.


Asunto(s)
Diabetes Mellitus Tipo 2/prevención & control , Obesidad/prevención & control , Consentimiento Paterno/estadística & datos numéricos , Negativa a Participar/estadística & datos numéricos , Estudiantes/estadística & datos numéricos , Adolescente , Niño , Formularios de Consentimiento , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Grupos Minoritarios , Instituciones Académicas , Factores Socioeconómicos , Estados Unidos
3.
Lipids ; 43(3): 243-9, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18256867

RESUMEN

Lysophosphatidylcholine (LysoPtdCho) levels are elevated in sera in patients with atherosclerosis and in atherosclerotic tissue. Previous studies have shown that reactive chlorinating species attack plasmalogens in human coronary artery endothelial cells (HCAEC), forming lysoPtdCho and lysoPtdCho-chlorohydrin (lysoPtdCho-ClOH). The results herein demonstrate for the first time that lysoPtdCho-ClOH is elevated over 60-fold in human atherosclerotic lesions. In cultured HCAEC, 18:0 lysoPtdCho-ClOH led to a statistically significant increase in P-selectin cell-surface expression, but unlike 18:1 lysoPtdCho did not lead to cyclooxygenase-2 protein expression. These data show that 18:0 lysoPtdCho-ClOH is elevated in atherosclerotic tissue and may have unique pro-atherogenic properties compared to lysoPtdCho.


Asunto(s)
Aterosclerosis/metabolismo , Clorhidrinas/análisis , Vasos Coronarios/metabolismo , Endotelio Vascular/metabolismo , Lisofosfatidilcolinas/análisis , Selectina-P/metabolismo , Aorta/química , Células Cultivadas , Clorhidrinas/sangre , Clorhidrinas/farmacología , Ciclooxigenasa 2/metabolismo , Células Endoteliales/metabolismo , Humanos , Lisofosfatidilcolinas/sangre , Lisofosfatidilcolinas/farmacología , Espectrometría de Masa por Ionización de Electrospray
4.
Perspect Health Inf Manag ; 2: 10, 2005 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-18066378

RESUMEN

Recently there has been increased focus on the need to modernize the healthcare information infrastructure in the United States. The U.S. healthcare industry is by far the largest in the world in both absolute dollars and in percentage of GDP (more than $1.5 trillion, or 15 percent of GDP). It is also fragmented and complex. These difficulties, coupled with an antiquated infrastructure for the collection of and access to medical data, lead to enormous inefficiencies and sources of error. Consumer, regulatory, and governmental pressure drive a growing consensus that the time has come to modernize the U.S. healthcare information infrastructure (HII). While such transformation may be disruptive in the short term, it will, in the future, significantly improve the quality, expediency, efficiency, and successful delivery of healthcare while decreasing costs to patients and payers and improving the overall experiences of consumers and providers. The launch of a national health infrastructure initiative in the United States in May 2004--with the goal of providing an electronic health record for every American within the next decade--will eventually transform the healthcare industry in general, just as information technology (IT) has transformed other industries in the past. The key to this successful outcome will be based on the way we apply IT to healthcare data and the services delivered through IT. This must be accomplished in a way that protects individuals and allows competition but gives caregivers reliable and efficient access to the data required to treat patients and to improve the practice of medical science. This paper describes key IT solutions and technologies that address the challenges of creating a nation-wide healthcare IT infrastructure. Furthermore we discuss the emergence of new electronic healthcare services and the current efforts of IBM Research, Software Group, and Healthcare Life Sciences to realize this new vision for healthcare.

5.
J Biol Chem ; 276(47): 43842-9, 2001 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-11571275

RESUMEN

Group IIa phospholipase A(2) (GIIa PLA(2)) is released by some cells in response to interleukin-1beta. The purpose of this study was to determine whether interleukin-1beta would stimulate the synthesis and release of GIIa PLA(2) from cardiomyocytes, and to define the role of p38 MAPK and cytosolic PLA(2) in the regulation of this process. Whereas GIIa PLA(2) mRNA was not identified in untreated cells, exposure to interleukin-1beta resulted in the sustained expression of GIIa PLA(2) mRNA. Interleukin-1beta also stimulated a progressive increase in cellular and extracellular GIIa PLA(2) protein levels and increased extracellular PLA(2) activity 70-fold. In addition, interleukin-1beta stimulated the p38 MAPK-dependent activation of the downstream MAPK-activated protein kinase, MAPKAP-K2. Treatment with the p38 MAPK inhibitor, SB202190, decreased interleukin-1beta stimulated MAPKAP-K2 activity, GIIa PLA(2) mRNA expression, GIIa PLA(2) protein synthesis, and the release of extracellular PLA(2) activity. Infection with an adenovirus encoding a constitutively active form of MKK6, MKK6(Glu), which selectively phosphorylates p38 MAPK, induced cellular GIIa PLA(2) protein synthesis and the release of GIIa PLA(2) and increased extracellular PLA(2) activity 3-fold. In contrast, infection with an adenovirus encoding a phosphorylation-resistant MKK6, MKK6(A), did not result in GIIa PLA(2) protein synthesis or release by unstimulated cardiomyocytes. In addition, infection with an adenovirus encoding MKK6(A) abrogated GIIa PLA(2) protein synthesis and release by interleukin-1beta-stimulated cells. These results provide direct evidence that p38 MAPK activation was necessary for interleukin-1beta-induced synthesis and release of GIIa PLA(2) by cardiomyocytes.


Asunto(s)
Regulación Enzimológica de la Expresión Génica/fisiología , Interleucina-1/farmacología , Proteínas Quinasas Activadas por Mitógenos/fisiología , Miocardio/enzimología , Fosfolipasas A/genética , Animales , Animales Recién Nacidos , Activación Enzimática , Corazón/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular , Miocardio/citología , Fosfolipasas A/biosíntesis , Fosfolipasas A/metabolismo , Fosfolipasas A2 , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Proteínas Quinasas p38 Activadas por Mitógenos
6.
Am J Physiol Heart Circ Physiol ; 281(1): H168-76, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11406482

RESUMEN

In isolated, perfused adult rat hearts, global ischemia increased the phosphorylation of cAMP response element-binding protein (CREB) relative to control levels, and this phosphorylation was reversed with reperfusion. CREB phosphorylation elicited by 5 min of global ischemia was sensitive to treatments with the calcium-independent phospholipase A(2) (iPLA(2)) inhibitor bromoenol lactone (BEL) and occurred in the absence of increases in myocardial cAMP content. In contrast, CREB phosphorylation elicited by 15 min of global ischemia was likely mediated by elevated cAMP levels. The expression of c-fos, in response to brief myocardial ischemia, was also sensitive to BEL treatment. The induction of iPLA(2)-mediated CREB phosphorylation was further substantiated by the observations that lysoplasmenylcholine increased both the phosphorylation of CREB and the induction of c-fos expression in the absence and presence of BEL. CREB phosphorylation in both ischemic hearts and lysoplasmenylcholine-perfused hearts was inhibited by pretreatment of hearts with the specific cAMP-dependent protein kinase (PKA) inhibitor H-89. Taken together, these data demonstrate that iPLA(2) mediates CREB phosphorylation through a PKA-dependent pathway during brief periods of myocardial ischemia, possibly through the formation of lysophospholipids.


Asunto(s)
Calcio/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Isquemia Miocárdica/metabolismo , Fosfolipasas A/fisiología , Proteínas Proto-Oncogénicas c-fos/metabolismo , 8-Bromo Monofosfato de Adenosina Cíclica/farmacología , Animales , Transporte Biológico , Lisofosfolípidos/farmacología , Masculino , Naftalenos/farmacología , Fosfolipasas A/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-fos/genética , Pironas/farmacología , ARN Mensajero/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley
7.
J Clin Invest ; 107(7): 813-22, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11285300

RESUMEN

Inherited and acquired cardiomyopathies are associated with marked intracellular lipid accumulation in the heart. To test the hypothesis that mismatch between myocardial fatty acid uptake and utilization leads to the accumulation of cardiotoxic lipid species, and to establish a mouse model of metabolic cardiomyopathy, we generated transgenic mouse lines that overexpress long-chain acyl-CoA synthetase in the heart (MHC-ACS). This protein plays an important role in vectorial fatty acid transport across the plasma membrane. MHC-ACS mice demonstrate cardiac-restricted expression of the transgene and marked cardiac myocyte triglyceride accumulation. Lipid accumulation is associated with initial cardiac hypertrophy, followed by the development of left-ventricular dysfunction and premature death. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and cytochrome c release in transgenic hearts suggest that cardiac myocyte death occurs, in part, by lipid-induced programmed cell death. Taken together, our data demonstrate that fatty acid uptake/utilization mismatch in the heart leads to accumulation of lipid species toxic to cardiac myocytes. This novel mouse model will provide insight into the role of perturbations in myocardial lipid metabolism in the pathogenesis of inherited and acquired forms of heart failure.


Asunto(s)
Cardiomiopatía Dilatada/metabolismo , Insuficiencia Cardíaca/metabolismo , Metabolismo de los Lípidos , Miocardio/metabolismo , Proteínas Represoras , Proteínas de Saccharomyces cerevisiae , Animales , Cardiomiopatía Dilatada/etiología , Células Cultivadas , Coenzima A Ligasas/biosíntesis , Coenzima A Ligasas/genética , Modelos Animales de Enfermedad , Femenino , Insuficiencia Cardíaca/etiología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocardio/citología
8.
J Biol Chem ; 276(26): 23733-41, 2001 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-11301330

RESUMEN

Plasmalogens contain a vinyl ether bond linking the sn-1 aliphatic chain to the glycerol backbone of this predominant phospholipid molecular subclass, which is found in many mammalian tissues. The present study demonstrates that the vinyl ether bond of plasmalogens is a molecular target of the reactive chlorinating species produced by myeloperoxidase. Analysis by thin layer chromatography revealed that reactive chlorinating species produced by myeloperoxidase target the vinyl ether bond of the plasmalogen, lysoplasmenylcholine (1-O-hexadec-1'-enyl-sn-glycero-3-phosphorylcholine), resulting in the production of a neutral lipid. Capillary gas chromatographic analyses demonstrated that the neutral lipid generated from lysoplasmenylcholine was neither hexadecanal nor did it contain masked hexadecanal (i.e. the vinyl ether) because the dimethyl acetal of hexadecanal produced by acid methanolysis derivatization was no longer present. Electrospray ionization mass spectrometry of the myeloperoxidase-generated neutral lipid product was consistent with the production of a 16-carbon fatty aldehyde containing one chlorine atom. Furthermore, proton NMR analysis indicated that this neutral lipid product was a 2-chloro-fatty aldehyde. Additional structural analysis of this neutral lipid by gas chromatography-mass spectrometry of the underivatized product as well as its pentafluorobenzyl oxime-derivative product was consistent with the neutral lipid being 2-chlorohexadecanal. The reactive chlorinating species, hypochlorous acid and chlorine gas, both attacked the vinyl ether bond of lysoplasmenylcholine resulting in the production of 2-chlorohexadecanal. The production of 2-chlorohexadecanal was dependent on the presence of the plasmalogen masked aldehyde (i.e. the vinyl ether) in the substrate because the free fatty aldehyde, hexadecanal, was not converted to 2-chlorohexadecanal by the reactive chlorinating species generated by myeloperoxidase. Taken together, the present studies demonstrate for the first time the targeting of the vinyl ether bond of plasmalogens by the reactive chlorinating species produced by myeloperoxidase resulting in the production of novel chlorinated fatty aldehydes.


Asunto(s)
Aldehídos/análisis , Cloro/química , Ácido Hipocloroso/química , Peroxidasa/metabolismo , Plasmalógenos/metabolismo , Animales , Cloro/metabolismo , Cromatografía de Gases , Cromatografía en Capa Delgada , Concentración de Iones de Hidrógeno , Ácido Hipocloroso/metabolismo , Lisofosfatidilcolinas/biosíntesis , Lisofosfolípidos/metabolismo , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Peroxidasa/antagonistas & inhibidores , Compuestos de Vinilo/metabolismo
9.
AORN J ; 73(2): 446-50, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11218931

RESUMEN

Issues in aseptic technique challenge every perioperative practitioner. Equally challenging for educators is how to creatively present information to large groups of staff members in a way that facilitates learning. This article describes the process used to address practice issues in aseptic technique and to present educational inservice programs to a large number of staff members. Two clinical educators formed a work group comprising staff RNs and surgical technologists to address this topic. Work group members then planned and presented a two-part education session to review these issues with surgical staff members.


Asunto(s)
Asepsia , Infección Hospitalaria/prevención & control , Enfermería de Quirófano/educación , Infección de la Herida Quirúrgica/prevención & control , Recursos Audiovisuales , Humanos , Capacitación en Servicio/métodos , Capacitación en Servicio/organización & administración , Medio Oeste de Estados Unidos , Ingenio y Humor como Asunto
10.
J Lipid Res ; 41(10): 1585-95, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11013300

RESUMEN

The role of nuclear membrane phospholipids as targets of phospholipases resulting in the generation of nuclear signaling messengers has received attention. In the present study, we have exploited the utility of electrospray ionization mass spectrometry to determine the phospholipid content of nuclei isolated from perfused hearts. Rat heart nuclei contained choline glycerophospholipids composed of palmitoyl and stearoyl residues at the sn-1 position with oleoyl, linoleoyl, and arachidonoyl residues at the sn-2 position. Diacyl molecular species were the predominant molecular subclass in the choline glycerophospholipids, with the balance of the molecular species being plasmalogens. In the ethanolamine glycerophospholipid pool from rat heart nuclei approximately 50% of the molecular species were plasmalogens, which were enriched with arachidonic acid at the sn-2 position. A 50% loss of myocytic nuclear choline and ethanolamine glycerophospholipids was observed in hearts rendered globally ischemic for 15 min followed by 90 min of reperfusion in comparisons with the content of these phospholipids in control perfused hearts. The loss of nuclear choline and ethanolamine glycerophospholipids during reperfusion of ischemic myocardium was partially reversed by the calcium-independent phospholipase A(2) (iPLA(2)) inhibitor bromoenol lactone (BEL), suggesting that the loss of nuclear phospholipids during ischemia/reperfusion is mediated, in part, by iPLA(2). Western blot analyses of isolated nuclei from ischemic hearts demonstrated that iPLA(2) is translocated to the nucleus after myocardial ischemia. Taken toghether, these studies have demonstrated that nuclear phospholipid mass decreases after myocardial ischemia by a mechanism that involves, at least in part, phospholipolysis mediated by iPLA2.


Asunto(s)
Isquemia Miocárdica/metabolismo , Membrana Nuclear/química , Fosfolípidos/metabolismo , Reperfusión/efectos adversos , Espectrometría de Masa por Ionización de Electrospray , Transporte Activo de Núcleo Celular , Animales , Western Blotting , Núcleo Celular/enzimología , Cinética , Masculino , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/terapia , Miocardio/química , Miocardio/patología , Miocardio/ultraestructura , Membrana Nuclear/metabolismo , Fosfatidilcolinas/análisis , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/análisis , Fosfatidiletanolaminas/metabolismo , Fosfolipasas A/metabolismo , Ratas , Ratas Sprague-Dawley
11.
J Immunol ; 164(4): 2084-91, 2000 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-10657662

RESUMEN

The purpose of this study was to define the role of secretory phospholipase A2 (sPLA2), calcium-independent PLA2, and cytosolic PLA2 (cPLA2) in arachidonic acid (AA) release from fMLP-stimulated human neutrophils. While fMLP induced the release of extracellular sPLA2 activity and AA, 70% of sPLA2 activity remained associated with the cell. Treatment with the cell-impermeable sPLA2 inhibitors DTT or LY311-727, or the anti-sPLA2 Ab 3F10 all inactivated extracellular sPLA2 activity, but had minimal effect on neutrophil AA mass release. In contrast, coincubation of streptolysin-O toxin-permeabilized neutrophils with DTT, LY311-727, or 3F10 all decreased [3H8]AA release from [3H8]AA-labeled, fMLP-stimulated cells. Exposure to fMLP resulted in a decrease in the electrophoretic mobility of cPLA2, a finding consistent with cPLA2 phosphorylation, and stimulated the translocation of cPLA2 from cytosolic to microsomal and nuclear compartments. The role of cPLA2 was further evaluated with the cPLA2 inhibitor methyl arachidonyl fluorophosphonate, which attenuated cPLA2 activity in vitro and decreased fMLP-stimulated AA mass release by intact neutrophils, but had no effect on neutrophil sPLA2 activity. Inhibition of calcium-independent PLA2 with haloenol lactone suicide substrate had no effect on neutrophil cPLA2 activity or AA mass release. These results indicate a role for cPLA2 and an intracellular or cell-associated sPLA2 in the release of AA from fMLP-stimulated human neutrophils.


Asunto(s)
Ácido Araquidónico/metabolismo , Citosol/enzimología , Neutrófilos/enzimología , Neutrófilos/metabolismo , Fosfolipasas A/metabolismo , Calcio/fisiología , Separación Celular , Activación Enzimática , Humanos , Líquido Intracelular/enzimología , Fosfolipasas A/fisiología , Fosfolipasas A2 , Especificidad por Sustrato
12.
Biochemistry ; 38(12): 3591-8, 1999 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-10090745

RESUMEN

The phospholipid composition requirements for optimal prothrombin activation and factor Va inactivation by activated protein C (APC) anticoagulant were examined. Vesicles composed of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) supported factor Va inactivation relatively well. However, optimal factor Va inactivation still required relatively high concentrations of phosphatidylserine (PS). In addition, at a fixed concentration of phospholipid, PS, and APC, vesicles devoid of PE never attained a rate of factor Va inactivation achievable with vesicles containing PE. Polyunsaturation of any vesicle component also contributed significantly to APC inactivation of factor Va. Thus, PE makes an important contribution to factor Va inactivation that cannot be mimicked by PS. In the absence of polyunsaturation in the other membrane constituents, this contribution was dependent upon the presence of both the PE headgroup per se and unsaturation of the 1,2 fatty acids. Although PE did not affect prothrombin activation rates at optimal PS concentrations, PE reduced the requirement for PS approximately 10-fold. The Km(app) for prothrombin and the Kd(app) for factor Xa-factor Va decreased as a function of increasing PS concentration, reaching optimal values at 10-15% PS in the absence of PE but only 1% PS in the presence of PE. Fatty acid polyunsaturation had minimal effects. A lupus anticoagulant immunoglobulin was more inhibitory to both prothrombinase and factor Va inactivation in the presence of PE. The degree of inhibition of APC was significantly greater and much more dependent on the phospholipid composition than that of prothrombinase. Thus, subtle changes in the phospholipid composition of cells may control procoagulant and anticoagulant reactions differentially under both normal and pathological conditions.


Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Factor Va/metabolismo , Fosfatidiletanolaminas/farmacología , Fosfatidilserinas/farmacología , Protrombina/metabolismo , Humanos , Inhibidor de Coagulación del Lupus/inmunología , Inhibidor de Coagulación del Lupus/metabolismo , Lípidos de la Membrana/química , Lípidos de la Membrana/farmacología , Fosfatidilcolinas/farmacología , Inhibidor de Proteína C/farmacología
13.
Am J Physiol ; 276(2): H642-50, 1999 02.
Artículo en Inglés | MEDLINE | ID: mdl-9950866

RESUMEN

The present study demonstrates that the alpha, epsilon, and iota isozymes of protein kinase C (PKC) are translocated to particulate fractions from the cytosol during brief intervals of global ischemia as well as reperfusion of ischemic rat myocardium. In contrast, phorbol ester treatment of perfused hearts resulted in the translocation of the alpha, delta, and epsilon isozymes of PKC to particulate fractions. Additionally, the alpha, delta, and epsilon isozymes of PKC are translocated to particulate fractions in phorbol ester-stimulated, isolated adult rat cardiac myocytes. Concomitant with the translocation of PKC isozymes to particulate fractions during myocardial ischemia, increased protein phosphorylation was observed, which was blocked by pretreatment of hearts with the selective PKC inhibitor bisindolylmaleimide I (50 nM). In particular, ischemia resulted in the phosphorylation of 26-, 20-, and 17-kDa particulate-associated proteins. Taken together, the present findings are the first to demonstrate that specific PKC isozymes are translocated to particulate fractions in the ischemic and the reperfused ischemic rat heart, resulting in the phosphorylation of specific particulate-associated proteins.


Asunto(s)
Isquemia Miocárdica/metabolismo , Fosfoproteínas/biosíntesis , Biosíntesis de Proteínas/fisiología , Proteína Quinasa C/fisiología , Animales , Técnicas In Vitro , Isoenzimas/metabolismo , Masculino , Isquemia Miocárdica/enzimología , Daño por Reperfusión Miocárdica/metabolismo , Miocardio/enzimología , Miocardio/patología , Proteína Quinasa C/metabolismo , Ratas , Ratas Sprague-Dawley , Acetato de Tetradecanoilforbol/farmacología
14.
FEBS Lett ; 438(1-2): 32-6, 1998 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-9821954

RESUMEN

Protein kinase C (PKC) has been suggested to mediate, at least in part, multiple processes in the pathophysiological sequelae of myocardial ischemia. The present study demonstrates that the epsilon, eta and iota isozymes of PKC are translocated to nuclei in response to brief intervals of global ischemia as well as reperfusion of ischemic rat myocardium. Concomitant with the translocation of PKC isozymes to nuclei during ischemia, increased PKC-mediated nuclear protein phosphorylation was observed. Taken together, the present results demonstrate that nuclear signaling mechanisms are activated during myocardial ischemia that include PKC translocation and PKC-mediated nuclear protein phosphorylation.


Asunto(s)
Núcleo Celular/metabolismo , Isoenzimas/metabolismo , Isquemia Miocárdica/metabolismo , Miocardio/metabolismo , Proteínas Nucleares/metabolismo , Proteína Quinasa C/metabolismo , Animales , Biomarcadores/análisis , Western Blotting , Fraccionamiento Celular , Núcleo Celular/enzimología , Citosol/metabolismo , Indoles/farmacología , Masculino , Maleimidas/farmacología , Isquemia Miocárdica/enzimología , Reperfusión Miocárdica , Miocardio/enzimología , Fosforilación , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C-epsilon , Ratas , Ratas Sprague-Dawley
15.
Biochemistry ; 37(34): 11953-61, 1998 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-9718320

RESUMEN

Protein kinase C (PKC) translocation to specific subcellular membrane loci after cellular stimulation is mediated, in part, through its interaction with diacylglycerol, phosphatidylserine, and calcium. Herein, we present multiple lines of evidence which demonstrate that purified rabbit brain PKC undergoes specific acylation with palmitoyl CoA that facilitates its interaction with membrane bilayers. First, incubation of purified rabbit brain PKC with [14C]palmitoyl CoA (5 microM) resulted in the radiolabeling of an 80 kDa band demonstrated by SDS-PAGE and autoradiography, while incubation of PKC with other acyl CoA molecular species (e.g., [3H]myristoyl CoA or [14C]arachidonoyl CoA), fatty acids (e.g., [14C]palmitic and [14C]arachidonic acid), or [14C]diacylglycerol did not result in the incorporation of radiolabel. Second, multiple extractions of [14C]palmitoyl CoA-treated PKC with butanol did not remove the radiolabeled moiety from the 80 kDa PKC band. Third, incubation of the [14C]palmitoyl CoA-radiolabeled PKC moiety with neutral hydroxylamine, hydrochloric acid, or sodium hydroxide released incorporated radiolabel which identified the association between PKC and palmitic acid as a covalent thioester linkage. Fourth, formation of the [14C]palmitoyl CoA-radiolabeled PKC adduct could be prevented by pretreatment of PKC with either dithiobis(nitrobenzoic acid) or N-ethylmaleimide. Fifth, limited trypsinolysis of palmitoylated PKC demonstrated that palmitic acid was exclusively present in the regulatory fragment of PKC without detectable amounts of palmitic acid associated with the catalytic fragment. Sixth, palmitoylated PKC was resolved from its nonpalmitoylated counterpart by Mono Q chromatography, and palmitoylated PKC preferentially associated with cellular membranes while nonpalmitoylated PKC did not. Both palmitoylated and nonpalmitoylated PKC were activated by phosphatidylserine, diacylglycerol, and calcium ion. Collectively, these results demonstrate the acylation of PKC by palmitoyl CoA and identify a novel mechanism which may facilitate the interaction of PKC with biologic membranes.


Asunto(s)
Encéfalo/enzimología , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Palmitoil Coenzima A/metabolismo , Acilación , Animales , Transporte Biológico , Encéfalo/metabolismo , Membrana Celular/enzimología , Membrana Celular/metabolismo , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Proteínas Quinasas Dependientes de AMP Cíclico/química , Hidrólisis , Masculino , Palmitoil Coenzima A/química , Conejos , Tripsina/metabolismo
16.
FEBS Lett ; 422(2): 247-51, 1998 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-9490017

RESUMEN

Since plasmalogens are the predominant phospholipid of cardiac sarcolemma, the activation of the sodium-calcium exchanger by either plasmenylethanolamine or plasmalogenic phosphatidic acid generated by phospholipase D was explored. Sodium-calcium exchange activity was 7-fold greater in proteoliposomes comprised of plasmenylethanolamine compared to proteoliposomes comprised of only plasmenylcholine. Phospholipase D treatment of proteoliposomes resulted in 1 mol % conversion of plasmenylcholine or phosphatidylcholine to their respective phosphatidic acid molecular species with a concomitant 8-fold or 2-fold activation of sodium-calcium exchange activity, respectfully. Thus, phospholipase D-mediated hydrolysis of plasmalogens to phosphatidic acid may be an important mechanism for the regulation of the sodium-calcium exchanger.


Asunto(s)
Miocardio/metabolismo , Ácidos Fosfatidicos/farmacología , Fosfolipasa D/metabolismo , Plasmalógenos/farmacología , Sarcolema/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Animales , Bovinos , Ventrículos Cardíacos , Liposomas , Ácidos Fosfatidicos/metabolismo , Plasmalógenos/metabolismo , Proteolípidos/metabolismo
17.
FEBS Lett ; 420(1): 33-8, 1997 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-9450545

RESUMEN

Plasmalogen-specific, calcium-independent phospholipase A2 (iPLA2) is activated during myocardial ischemia. Accordingly, we have assessed the activation of myocardial protein kinases by the iPLA2 product, lysoplasmenylcholine. Lysoplasmenylcholine-activated protein kinase activity from heart cytosol fractionated on a DE-52 column was identified as cAMP-dependent protein kinase (PKA) based on the following: (1) protein kinase activity stimulated by cAMP and lysoplasmenylcholine co-eluted on sequential chromatographic steps; (2) lysoplasmenylcholine-activated protein kinase activity was inhibited by the PKA inhibitor, PKI; and (3) the unprimed PKA form generated from the primed form of PKA was activated by cAMP and lysoplasmenylcholine. These results demonstrate a novel mechanism for PKA activation by lysoplasmenylcholine.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Lisofosfolípidos/farmacología , Miocardio/enzimología , Animales , Proteínas Portadoras/farmacología , Bovinos , Cromatografía por Intercambio Iónico/métodos , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Proteínas Quinasas Dependientes de AMP Cíclico/aislamiento & purificación , Citosol/enzimología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Miocardio/química , Oligopéptidos/metabolismo , Fosfoproteínas/análisis , Fosforilación , Conejos
18.
FEBS Lett ; 394(1): 99-102, 1996 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-8925938

RESUMEN

Although plasmalogens are the predominant phospholipids of cardiac sarcolemma, their physiological role has not been forthcoming. Since the cardiac sarcolemmal sodium-calcium exchanger has been proposed to be regulated by anionic phospholipids, the roles of plasmalogens and anionic phospholipids as regulators of the sodium-calcium exchanger were explored. Reconstituted sodium-calcium exchange activity in plasmalogen-containing proteoliposomes was 10-fold higher than that in control proteoliposomes comprised of only diacyl phospholipids. Additionally, exchange activity in plasmalogen-containing proteoliposomes was regulated by anionic phospholipids. Thus, plasmalogens provide a critical lipid environment in which anionic phospholipids serve as boundary lipids for the regulation of the trans-sarcolemmal sodium-calcium exchanger.


Asunto(s)
Proteínas Portadoras/metabolismo , Miocardio/metabolismo , Fosfolípidos/fisiología , Plasmalógenos/fisiología , Sarcolema/metabolismo , Secuencia de Aminoácidos , Animales , Bovinos , Liposomas/química , Liposomas/metabolismo , Datos de Secuencia Molecular , Péptidos/farmacología , Fosfatidilserinas/metabolismo , Fosfolípidos/química , Plasmalógenos/química , Intercambiador de Sodio-Calcio
19.
Biochemistry ; 35(24): 7903-9, 1996 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-8672492

RESUMEN

Long-chain acylcarnitines accumulate during myocardial ischemia and contribute to membrane dysfunction in ischemic zones. On the basis of the 3-fold selectivity for saturated fatty acid accumulation during myocardial ischemia, it was implicitly assumed that saturated long chain acylcarnitine molecular species predominantly accumulated in ischemic myocardium. By exploiting the analytical power of electrospray ionization mass spectroscopy, we now report that unsaturated acylcarnitines are the predominant molecular species of acylcarnitine which accumulate during myocardial ischemia (rank order: octadecadienoyl carnitine > octadecanoyl carnitine > hexadecanoyl carnitine > octadecanoyl carnitine). The aliphatic chain distribution of myocardial acylcarnitine molecular species identified by electrospray ionization mass spectroscopy was independently substantiated by sequential HPLC purification and capillary gas chromatography. Detailed analysis of the individual molecular species of long-chain acylcarnitine demonstrated that fatty acyl chain elongation was prominent in ischemic myocardium (e.g., following 20 min of ischemia, greater than 15% of the accumulated acylcarnitines consisted of 20-carbon unsaturated molecular species). Chain-elongated lipids were essentially confined to the long chain acylcarnitine pool since [9,10-3H]octadec-9'-enoic acid was converted to [3H]eicosenoyl carnitine (12% of the radiolabeled acylcarnitine pool) in ischemic hearts without substantive amounts of [3H]eicosenoyl residues in the fatty acid, triglyceride, and phospholipid pools. Collectively, these results demonstrate the preponderance of unsaturated acylcarnitines in ischemic myocardium and document the metabolic compartmentation of downstream products of fatty acyl chain elongation in the acylcarnitine pool during ischemia.


Asunto(s)
Carnitina/análogos & derivados , Carnitina/metabolismo , Isquemia Miocárdica/metabolismo , Miocardio/metabolismo , Animales , Carnitina/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Técnicas In Vitro , Cinética , Espectrometría de Masas , Fosfolípidos/aislamiento & purificación , Fosfolípidos/metabolismo , Conejos , Valores de Referencia , Relación Estructura-Actividad , Factores de Tiempo
20.
AORN J ; 63(3): 583-9, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8651669

RESUMEN

Clinical nurse educators are challenged continually to develop interesting and meaningful education sessions for staff members. At the Mayo Medical Center, Rochester, Minn, clinical nurse educators in the surgical services department created an education session based on the television game show Jeopardy. Staff members found they could remember information presented during the education session more easily because of the game show format.


Asunto(s)
Capacitación en Servicio/métodos , Enfermería Perioperatoria/educación , Juego e Implementos de Juego , Humanos , Capacitación en Servicio/organización & administración , Minnesota , Personal de Enfermería en Hospital/educación , Seguridad , Televisión , Precauciones Universales
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