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1.
Sci Total Environ ; 751: 141858, 2021 Jan 10.
Article in English | MEDLINE | ID: mdl-32892081

ABSTRACT

Over the last 10 years applied scientific research has been carried out in Romania to tacked the residential radon issues. The increased interest to reduce the carbon footprint of buildings has lead to the implementation and use of new architectural solutions aimed to save energy in houses and other buildings. As a consequence, the degree of retrofit in existing buildings and energy efficiency of new buildings promoted the need to not only mitigate indoor radon, but improve indoor air quality overall. The present study found that the while the best performance in radon reduction was confirmed to be based on sub-slab depressurization (61% - 95% reduction), centralized and decentralized mechanical supply and exhaust ventilation with heat recovery yielded a good efficiency in overall improvement of indoor air quality (CO2, VOC, RH, temperature). The outcome of our research, as well as future perspectives, take into account the recommended harmonization of energy efficiency programs with those of public health by finding and applying the best technologies in compliance with energy saving and indoor environmental quality.

2.
Ann Burns Fire Disasters ; 33(3): 253-261, 2020 Sep 30.
Article in English | MEDLINE | ID: mdl-33304217

ABSTRACT

Disaster myths pose a great challenge in disaster risk management all over the world. These misconceptions mean barriers to disaster higher education as well. This research is designed to examine these beliefs among disaster management students at the National University of Public Service, Hungary, as well as in a control group compiled from students from three other Hungarian universities. Based on the methodology of research published by David Alexander, a questionnaire was edited with 19 false statements about disaster events. Respondents had to evaluate them on a Likert scale from 1 to 5, where 1 means "completely disagree" and 5 means "completely agree". Strong agreement was expressed for some of the misconceptions regarding disasters (e.g. unburied bodies constitute a serious health hazard), and to a lesser degree for others (e.g. disasters cannot be managed systematically). The results of the control group reached similar values to those of the test groups, however in some cases the former tend to be more skeptical about the statements. Although Hungarian students shared the same beliefs as US and Italian students, the Hungarians seem to be less critical of the statements. These disaster myths create a serious problem in disaster higher education and have a great impact on future disaster managers in the field.


Les mythes concernant les catastrophes obèrent leur prise en charge, ce à travers le monde et interfèrent avec la formation en médecine de catastrophe (MC). Ce travail a pour but d'évaluer les croyances de 165 étudiants en MC de l'Université Nationale de Service Public (UNSP) et de les comparer à 100 témoins (T) recrutés dans d'autres universités hongroises. Un questionnaire élaboré à partir de la méthode publiée par David Alexander, comprenant 19 assertions fausses concernant les catastrophes a été distribué. Les réponses, selon l'échelle de Likert, étaient cotées de 1 (je suis fermement en désaccord) à 5 (j'agrée complétement). Certaines croyances, comme le risque sanitaire élevé lié aux corps non enterrés, étaient largement partagées, d'autres, comme l'impossibilité d'une prise en charge standardisée, l'étant plus modestement. Les réponses étaient comparables dans les 2 groupes, les étudiants de l'UNSP étant toutefois plus sceptiques dans certains cas. Les étudiants hongrois, bien que partageant les mêmes croyances que les italiens et les américains semblent toutefois moins critiques à leurs égards. Ces fausses réalités posent le problème de la formation MC en Hongrie et de la prise en charge sub-optimale d'une catastrophe.

3.
Nat Commun ; 11(1): 5601, 2020 11 05.
Article in English | MEDLINE | ID: mdl-33154374

ABSTRACT

The extent to which species can balance out the loss of suitable habitats due to climate warming by shifting their ranges is an area of controversy. Here, we assess whether highly efficient wind-dispersed organisms like bryophytes can keep-up with projected shifts in their areas of suitable climate. Using a hybrid statistical-mechanistic approach accounting for spatial and temporal variations in both climatic and wind conditions, we simulate future migrations across Europe for 40 bryophyte species until 2050. The median ratios between predicted range loss vs expansion by 2050 across species and climate change scenarios range from 1.6 to 3.3 when only shifts in climatic suitability were considered, but increase to 34.7-96.8 when species dispersal abilities are added to our models. This highlights the importance of accounting for dispersal restrictions when projecting future distribution ranges and suggests that even highly dispersive organisms like bryophytes are not equipped to fully track the rates of ongoing climate change in the course of the next decades.


Subject(s)
Bryophyta/physiology , Climate Change , Plant Dispersal/physiology , Bryophyta/classification , Bryophyta/growth & development , Ecosystem , Europe , Extinction, Biological , Forecasting , Models, Theoretical , Wind
4.
Sci Total Environ ; 669: 887-892, 2019 Jun 15.
Article in English | MEDLINE | ID: mdl-30897444

ABSTRACT

In the framework of the last Council Directive 2013/59 (Euratom, 2014) laying down basic safety standards for protection against the dangers arising from exposure to ionizing radiation, the problem of radon was assumed in Romania at national level by responsible authorities through the design and development of a National Radon Action Plan and an adequate legislation (HG nr. 526/2018). In order to identify radon risk areas, however, it is necessary to perform systematic radon measurements in different environmental media (soil gas, water, indoor air) and to map the results. This paper presents an atlas of up-to-date radon in soil and water levels for central and western part of Romania. The radon in soil map includes data from 2564 measurements carried out on-site, using Luk3C radon detector. The Luk-VR system was used to measure radon activity concentration from 2452 samples of drinking water. The average radon activity concentration was 29.3 kBq m-3 for soil gas, respectively 9.8 Bq l-1 for water dissolved air. Mapping of radon can be a useful tool to implement radon policies at both the national and local levels, defining priority areas for further study when land-use decisions must be made.

5.
Radiat Prot Dosimetry ; 181(1): 1-5, 2018 Sep 01.
Article in English | MEDLINE | ID: mdl-29897577

ABSTRACT

In many countries, caves can pose an economic interest for the authorities and stakeholders. The development of a show cave requires, apart from the conservation issues, to ensure the human safety by minimising the exposure to radon for cave personnel and visitors. Radon levels can vary widely from cave to cave, being directly correlated with different internal and external factors. It is therefore important to monitor radon levels before establishing the number of personnel required, so that they are not exposed to health-threatening levels of radiation. A long-term radon survey was carried out for this purpose in five show caves of Romania. The study pointed out the existence of high-radon potential areas inside the caves with concentrations reaching up to 4024 Bqm-3, thus posing radiological hazard to cave personnel and researchers who develop activities underground. Further research focused on personal dosimetry will be necessary for an efficient management of occupational risk.


Subject(s)
Air Pollutants, Radioactive/analysis , Caves , Radiation Exposure/analysis , Radiation Monitoring/methods , Radon/analysis , Humans , Romania
6.
Clin Pharmacol Ther ; 103(3): 511-520, 2018 03.
Article in English | MEDLINE | ID: mdl-28643328

ABSTRACT

As drug development is extremely expensive, the identification of novel indications for in-market drugs is financially attractive. Multiple algorithms are used to support such drug repurposing, but highly reliable methods combining simulation of intracellular networks and machine learning are currently not available. We developed an algorithm that simulates drug effects on the flow of information through protein-protein interaction networks, and used support vector machine to identify potentially effective drugs in our model disease, psoriasis. Using this method, we screened about 1,500 marketed and investigational substances, identified 51 drugs that were potentially effective, and selected three of them for experimental confirmation. All drugs inhibited tumor necrosis factor alpha-induced nuclear factor kappa B activity in vitro, suggesting they might be effective for treating psoriasis in humans. Additionally, these drugs significantly inhibited imiquimod-induced ear thickening and inflammation in the mouse model of the disease. All results suggest high prediction performance for the algorithm.


Subject(s)
Drug Repositioning/methods , Gene Regulatory Networks/genetics , Protein Interaction Domains and Motifs , Protein Interaction Maps , Algorithms , Animals , Cell Line , Computer Simulation , Dermatitis/drug therapy , Drug Evaluation, Preclinical , Ear, External/pathology , Humans , Imiquimod , Machine Learning , Mice , Mice, Inbred BALB C , NF-kappa B/drug effects , Psoriasis/chemically induced , Psoriasis/drug therapy , RNA/biosynthesis , RNA/genetics , Support Vector Machine , Tumor Necrosis Factor-alpha/antagonists & inhibitors
7.
Radiat Prot Dosimetry ; 177(1-2): 181-185, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-28981907

ABSTRACT

Measurements have been carried out using four types of passive detectors in four of the most popular show caves in Romania. Three types of detectors (RSKS, RadTrak and CD) were used for radon measurements and two (Raduet and CD) for thoron measurement. Activity concentrations in air were measured in the same locations for two seasons, autumn and winter. Measured values for the different caves varied between below detection limit (5 Bq m-3) and 4024 Bq m-3 for radon and from below 10 to 583 Bq m-3 for thoron. The results indicate a very good correlation between RSKS and RadTrak detectors (r = 0.96). The most significant difference between radon concentrations measured with different types of detectors (RSKS and CD) was higher than 150%. The study suggests that the activity concentration of radon in caves, measured using track detectors, could not be influenced by the type of detector used if the microclimate factor is acknowledged.


Subject(s)
Air Pollutants, Radioactive/analysis , Caves , Environmental Exposure/analysis , Radiation Monitoring/instrumentation , Radon/analysis , Limit of Detection , Radon Daughters/analysis , Romania , Seasons
8.
Radiat Prot Dosimetry ; 162(1-2): 96-100, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25031036

ABSTRACT

In the present study, the measurements of radon were carried out using the LUK-VR system based on radon gas measurements with Lucas cells. The radium concentration in water was determined, with the same device, immediately after was established the radon equilibrium with radium. The results presented here are from a survey carried out in the N-W region of Transylvania (Romania) in which were investigated the radon concentrations in natural (spring, well and surface) and drinking (tap) waters. The results showed radon concentrations within the range of 0.4-187.3 Bq l(-1) with an average value of 15.9 Bq l(-1) whereas radium concentration varied between 0.05 and 0.825 Bq l(-1) with an average value of 0.087 Bq l(-1) for all types of water covered within this survey. The corresponding annual effective ingestion dose due to radon and radium from water was determined from drinking water used by the population inhabiting the area.


Subject(s)
Air Pollution, Indoor/analysis , Drinking Water/analysis , Radiation Monitoring , Radium/analysis , Radon/analysis , Water Pollutants, Radioactive/analysis , Humans , Radiation Dosage , Romania , Water Supply/analysis , Water Wells/analysis
9.
J Environ Radioact ; 99(11): 1731-5, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18789562

ABSTRACT

We propose a new method to measure the (222)Rn concentration in a closed bore-hole and to use the results for estimation of the diffusion parameter and the average radium content of the surrounding geological formations. In a closed bore-hole, only several meters from the surface, the radon concentration is rather constant (in the +/-15% range) under different meteorological conditions. The inflow of radon gas, after removing the radon from the bore-hole by dry nitrogen, shows characteristic time-dependence, which is determined by the diffusion parameter for radon in the surrounding environment. The experimental data were well described by a straightforward model calculation. From the results estimate can be given for the diffusion parameter and for the average radium content of the surrounding geological formation.


Subject(s)
Geology , Radon/analysis , Meteorology , Nitrogen/chemistry
10.
J Chromatogr A ; 1079(1-2): 349-53, 2005 Jun 24.
Article in English | MEDLINE | ID: mdl-16038322

ABSTRACT

In order to support high-throughput library purification, a novel UV triggered fraction collection method was developed in which a maximum-seeking-algorithm-driven, six-port valve collects the largest chromatographic peak. This straightforward strategy achieves the one sample-one fraction approach, thus resulting in a simpler and less error prone workup procedure. The effectiveness of this main component fraction collection method will be illustrated here by the results of the purification of compound libraries (altogether 6086 compounds, having an averaged success rate of 79.4%). Advanced applications, where the desired component differs from the main component, will also be discussed.


Subject(s)
Chemical Fractionation/methods , Complex Mixtures/isolation & purification , Peptide Library , Spectrophotometry, Ultraviolet
11.
Leukemia ; 18(8): 1373-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15190260

ABSTRACT

Cyclooxygenase (COX)-1 or -2 and specific prostaglandin (PG) synthases catalyze the formation of various PGs. We investigated the expression and activity of COX-1 and -2 during granulocyte-oriented maturation induced by all-trans-retinoic acid (ATRA) of NB4 cells, originated from a human acute promyelocytic leukemia (APL), and in blasts from APL patients. The expression of COX isoenzymes or prostaglandin synthases was also investigated in circulating granulocytes and human bone marrow. COX-1 was expressed and enzymatically active in NB4 cells and primary blasts. COX-1 mRNA and protein were induced by ATRA. COX-1 protein increased approximately 2-3.5-fold by culture day 3 in NB4 cells and primary blasts, while basal COX-2 expression was very low and unaffected by ATRA. COX-1-dependent PGE(2) biosynthesis increased during differentiation approx. 5-fold. Indomethacin and the selective COX-1 inhibitor SC-560, but not selective COX-2 inhibition, impaired NB4 differentiation, reducing NADPH-oxidase activity, CD11b and CD11c expression. The immunohistochemistry of granulocytes and myeloid precursors in the bone marrow showed a large prevalence of COX-1 as compared to COX-2. In conclusion, COX-1 is induced during ATRA-dependent maturation and appears to contribute to myeloid differentiation both in vitro and ex vivo, and COX-1 activity may potentiate the differentiation of human APL.Leukemia (2004) 18, 1373-1379. doi:10.1038/sj.leu.2403407 Published online 10 June 2004


Subject(s)
Isoenzymes/biosynthesis , Leukemia, Promyelocytic, Acute/enzymology , Leukemia, Promyelocytic, Acute/pathology , Prostaglandin-Endoperoxide Synthases/biosynthesis , Up-Regulation , Blood Cells , Bone Marrow Cells , Cell Differentiation/drug effects , Cell Line, Tumor , Cyclooxygenase 1 , Cyclooxygenase 2 , Dinoprostone/biosynthesis , Granulocytes/cytology , Humans , Isoenzymes/analysis , Isoenzymes/genetics , Leukemia/enzymology , Leukemia/pathology , Membrane Proteins , Myelopoiesis/drug effects , Prostaglandin-Endoperoxide Synthases/analysis , Prostaglandin-Endoperoxide Synthases/genetics , RNA, Messenger/biosynthesis , Tretinoin/pharmacology , Tumor Cells, Cultured
13.
Biochem J ; 358(Pt 3): 559-68, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11535119

ABSTRACT

The molecular cloning of two previously unknown human sarco/endoplasmic reticulum Ca(2+)-ATPase 3 (SERCA3) 3'-end transcripts, 3b and 3c, has been recently published. Data were lacking, however, for the presence of these SERCA3 variants in different tissue or cell types at the protein level. Here we report the co-expression of three human SERCA3 protein isoforms in platelets and T lymphoid Jurkat cells. Isoform-specific polyclonal anti-peptide antibodies have been generated that recognize specifically the SERCA3a, 3b or 3c splice variants at their C-termini, and this has been confirmed by peptide-competition experiments as well. None of these antibodies cross-reacted with the housekeeping SERCA2b isoform co-expressed endogenously with SERCA3 proteins in non-muscle cells. Although all three SERCA3 isoforms could be detected in platelets, the 3a form was the most abundantly expressed species. Its size matched the apparent size of SERCA3a over-expressed in HEK-293 cells. Immunoprecipitation of the SERCA3 variants from platelet membranes using a PL/IM 430-affinity matrix provided evidence that the putative pan-anti-SERCA3 antibody, PL/IM 430, recognizes all SERCA3 protein isoforms. The epitope for the PL/IM 430 antibody could be localized in a 40 kDa N-terminal tryptic fragment common to all three SERCA3 variants. Comparative Western-blot analysis showed that the expression level of the SERCA3a, 3b and 3c isoforms was more than 10 times lower in Jurkat cells than in platelets, whereas expression of the ubiquitous SERCA2b was nearly identical. This work highlights new Ca(2+)-transporting proteins of haematopoietic cells and provides specific antibodies for their detection.


Subject(s)
Alternative Splicing , Blood Platelets/enzymology , Calcium-Transporting ATPases/genetics , Endoplasmic Reticulum/enzymology , Genetic Variation , Sarcoplasmic Reticulum/enzymology , T-Lymphocytes/enzymology , Amino Acid Sequence , Calcium-Transporting ATPases/chemistry , Cell Line , Epitopes/chemistry , Humans , Isoenzymes/chemistry , Isoenzymes/genetics , Jurkat Cells , Molecular Sequence Data , Peptide Fragments/chemistry , Recombinant Proteins/biosynthesis , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Transcription, Genetic , Transfection
15.
Genetics ; 156(4): 1901-12, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11102383

ABSTRACT

The Ketel(D) dominant female-sterile mutations and their ketel(r) revertant alleles identify the Ketel gene, which encodes the importin-beta (karyopherin-beta) homologue of Drosophila melanogaster. Embryogenesis does not commence in the Ketel(D) eggs deposited by the Ketel(D)/+ females due to failure of cleavage nuclei formation. When injected into wild-type cleavage embryos, cytoplasm of the Ketel(D) eggs does not inhibit nuclear protein import but prevents cleavage nuclei formation following mitosis. The Ketel(+) transgenes slightly reduce effects of the Ketel(D) mutations. The paternally derived Ketel(D) alleles act as recessive zygotic lethal mutations: the Ketel(D)/- hemizygotes, like the ketel(r)/ketel(r) and the ketel(r)/- zygotes, perish during second larval instar. The Ketel maternal dowry supports their short life. The Ketel(D)-related defects originate most likely following association of the Ketel(D)-encoded mutant molecules with a maternally provided partner. As in the Ketel(D) eggs, embryogenesis does not commence in eggs of germline chimeras with ketel(r)/- germline cells and normal soma, underlining the dominant-negative nature of the Ketel(D) mutations. The ketel(r) homozygous clones are fully viable in the follicle epithelium in wings and tergites. The Ketel gene is not expressed in most larval tissues, as revealed by the expression pattern of a Ketel promoter-lacZ reporter gene.


Subject(s)
Cell Nucleus/ultrastructure , Drosophila melanogaster/genetics , Genes, Dominant , Genes, Insect , Genomic Imprinting , Insect Proteins/genetics , Nuclear Proteins/genetics , Alleles , Animals , Animals, Genetically Modified , Cell Nucleus/metabolism , Chimera , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Embryo, Nonmammalian/metabolism , Female , Gene Expression Regulation, Developmental , Genes, Lethal , Genes, Reporter , Infertility, Female/genetics , Insect Proteins/physiology , Karyopherins , Larva , Microinjections , Nuclear Proteins/physiology , Phenotype , Protein Transport/genetics , Transgenes , Wings, Animal/cytology , Zygote
16.
Biochem J ; 350 Pt 3: 723-34, 2000 Sep 15.
Article in English | MEDLINE | ID: mdl-10970785

ABSTRACT

The endoplasmic reticulum (ER) plays a key role in Ca(2+) signalling through Ca(2+) release via inositol 1,4,5-trisphosphate receptors (InsP(3)-Rs) and Ca(2+) uptake by sarco/endoplasmic reticulum Ca(2+)-ATPases (SERCAs). Here, we investigated the organization of platelet ER and its biogenesis during megakaryocytopoiesis. First, erythro/megakaryoblastic MEG 01, UT7, M-O7e and CHRF 288-11 cell lines, platelets and thrombopoietin-induced UT7-Mpl cells were selected for the study of SERCA2b and SERCA3 proteins by Western blotting using the antibodies IID8 and PL/IM430, respectively. As judged by platelet glycoprotein IIIa (GPIIIa) expression, an increase in SERCA3 proteins was observed while that of SERCA2b remained unchanged throughout maturation. Second, these studies were extended to the newly described alternatively spliced SERCA3a-c RNAs and InsP(3)-Rs using the in vitro model of PMA-induced differentiation of MEG 01 cells. Time-course and dose-response studies showed a maximal approx. 4-fold up-regulation of SERCA3 proteins using 10(-8) M PMA for 3 days, which paralleled induction of GPIIIa expression. SERCA3 induction was found to occur at the level of mRNA. The modulation of the different SERCA3 species (i.e. 3a, 3b and 3c) was isoform-specific: while SERCA3a was slightly increased, an approx. 3-fold induction of SERCA3b, and a 4-fold induction of SERCA3c, was observed after 24 h of PMA treatment. Isoform-specific Western blotting and/or reverse transcriptase PCR studies showed that InsP(3)-R types I, II and III are expressed in MEG 01 cells, as well as in platelets. Study of the expression of these InsP(3)-R types in PMA-induced MEG 01 cells revealed that: (i) InsP(3)-RI protein and mRNA showed no changes; (ii) InsP(3)-RII mRNA was up-regulated and peaked at hour 48 and (iii) InsP(3)-RIII mRNA and protein showed a transitory maximal 3- and 2.3-fold increase at hours 6 and 30, respectively. Upon PMA treatment of CHRF 288-11 cells, in which GPIIIa is not induced upon treatment, a similar pattern of regulation of InsP(3)-R types II and III was seen, but a distinct pattern of SERCA3 regulation was observed. These results suggest a profound reorganization of ER-protein patterns during megakaryocytopoiesis and underline the role of SERCA3 gene regulation in the control of Ca(2+)-dependent platelet functions.


Subject(s)
Calcium Signaling , Calcium-Transporting ATPases/metabolism , Cell Differentiation , Endoplasmic Reticulum/metabolism , Megakaryocytes/cytology , Cell Differentiation/drug effects , Fluorescent Antibody Technique , Humans , Tetradecanoylphorbol Acetate/pharmacology
17.
Trends Ecol Evol ; 15(9): 351-352, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10931666
18.
Hypertension ; 35(1 Pt 1): 91-102, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10642281

ABSTRACT

Gaining insight into nonmuscle Ca(2+) signaling requires basic knowledge of the major structures involved. We investigated the expression of platelet Ca(2+)ATPases in normal and hypertension-associated abnormal Ca(2+) signaling. First, overall identification of normotensive Wistar-Kyoto rat Ca(2+)ATPases was attempted by looking for newly described human platelet 3'-end alternatively spliced sarco/endoplasmic reticulum Ca(2+)ATPases (SERCA) 3b mRNA and plasma membrane Ca(2+)ATPase (PMCA) 1b and 4b proteins, in addition to SERCA2b and SERCA3a isoforms. For SERCAs, comparative analyses of human and Wistar-Kyoto rat SERCA3 platelet mRNA by reverse transcription-polymerase chain reaction (RT-PCR) followed by sequencing established that human platelets coexpressed SERCA3b and a third SERCA3c, while rat cells were devoid of them but expressed a still unknown splice variant that we termed rSERCA3b/3c. Its identification using 3'-end SERCA3 gene and rapid amplification of cDNA ends (RACE)-PCR studies showed that it results from an additional SERCA3 alternative splicing process, which uses a second alternative polyadenylation site located in the last intron. For PMCAs, with the use of gene-specific RT-PCR followed by sequencing and Western blotting using 5F10 monoclonal antibody, expression of human and rat platelet PMCA1b and PMCA4b was similar. Second, comparative analysis of these newly identified Ca(2+)ATPases and SERCA3a in age-matched spontaneously hypertensive rat platelets demonstrated (1) a marked downregulation of rSERCA3b/3c, which became null, and a 1.71-fold increase in SERCA3a and (2) an opposite regulation of the 2 PMCAs, namely, a 3.3-fold decrease in PMCA1b mRNA and a 3.7-fold increase in PMCA4b mRNA. Hence, platelets coexpress multiple, diverse, and species-specific Ca(2+)ATPases, including a novel fourth SERCA3. Moreover, expression of PMCA (1b and 4b), SERCA3a, and rSERCA3b/3c was modulated in rat hypertension. Hence, Ca(2+)ATPases should be regarded as constituting a new rational basis for the understanding of nonmuscle cell Ca(2+) signaling.


Subject(s)
Blood Platelets/enzymology , Calcium-Transporting ATPases/blood , Calcium-Transporting ATPases/genetics , Hypertension/enzymology , Hypertension/genetics , Adult , Alternative Splicing , Amino Acid Sequence , Animals , Base Sequence , Calcium Signaling , Cell Membrane/enzymology , DNA Primers/genetics , DNA, Complementary/genetics , Endoplasmic Reticulum/enzymology , HeLa Cells , Humans , In Vitro Techniques , Isoenzymes/blood , Isoenzymes/genetics , Molecular Sequence Data , RNA, Messenger/blood , RNA, Messenger/genetics , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Sarcoplasmic Reticulum/enzymology , Species Specificity
19.
Blood ; 93(12): 4395-405, 1999 Jun 15.
Article in English | MEDLINE | ID: mdl-10361138

ABSTRACT

Calcium is accumulated from the cytosol into the endoplasmic reticulum by sarco-endoplasmic reticulum calcium transport ATPase (SERCA) enzymes. Because calcium stored in the endoplasmic reticulum is essential for cell growth, differentiation, calcium signaling, and apoptosis and because different SERCA enzymes possess distinct functional characteristics, in the present report we explored SERCA expression during in vitro differentiation of the human myeloid/promyelocytic cell lines HL-60 and NB4 and of freshly isolated acute promyelocytic leukemia cells. Two SERCA species have been found to be coexpressed in these cells: SERCA 2b and another isoform, SERCAPLIM, which is recognized by the PLIM430 monoclonal antibody. Induction of differentiation along the neutrophil granulocytic lineage by all-trans retinoic acid or cyclic AMP analogs led to an increased expression of SERCAPLIM, whereas the expression of the SERCA 2b isoform was decreased. The modulation of SERCA expression was manifest also on the mRNA level. Experiments with retinoic acid receptor isoform-specific retinoids indicated that SERCA expression is modulated by retinoic acid receptor alpha-dependent signaling. SERCA expression of retinoic acid-resistant cell variants was refractory to treatment. Differentiation along the monocyte/macrophage lineage by phorbol ester resulted in an increased expression of both SERCA isoforms. In addition, when cells were treated by phorbol ester in the presence of the glucocorticoid dexamethasone, a known inhibitor of monocyte differentiation, a selective blockage of the induction of SERCAPLIM was observed. Altered SERCA expression modified the functional characteristics of calcium transport into the endoplasmic reticulum. These observations show for the first time that the modulation of calcium pump expression is an integral component of the differentiation program of myeloid precursors and indicate that a lineage-specific remodelling of the endoplasmic reticulum occurs during cell maturation. In addition, these data show that SERCA isoforms may serve as useful markers for the study of myeloid differentiation.


Subject(s)
Calcium-Transporting ATPases/genetics , Calcium/metabolism , Cell Differentiation , Gene Expression , Granulocytes/metabolism , Cyclic AMP/pharmacology , Drug Resistance , Endoplasmic Reticulum/enzymology , Granulocytes/cytology , Humans , Kinetics , Leukemia, Promyelocytic, Acute , Macrophages , RNA, Messenger/metabolism , Sarcoplasmic Reticulum/enzymology , Tetradecanoylphorbol Acetate/pharmacology , Tretinoin/pharmacology , Tumor Cells, Cultured
20.
Cell Calcium ; 24(2): 129-35, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9803313

ABSTRACT

Antibodies 5F10 and JA3 (raised against the erythrocyte Ca2+ pump) were used to identify hPMCA4b as the major form of the plasma membrane Ca2+ pump in human platelets and in three human megakaryoblastoid cell lines, MEG 01, DAMI and CHRF 288-11. 5F10 was used because it has been shown to recognize all known isoforms of the hPMCA and JA3 because it reacts exclusively with hPMCA4b [Caride A.J., Filoteo A.G., Enyedi A., Verma A.K., Penniston J.T. Detection of isoform 4 of the plasma membrane calcium pump in human tissues by using isoform-specific monoclonal antibodies. Biochem J 1996; 316: 353-359]. In addition to hPMCA4b, hPMCA1b was also detected in the megakaryoblastoid cells by using isoform-specific polyclonal antibodies. The apparent size of this isoform, however, was smaller than that seen in HeLa and COS-7 cell membranes indicating the presence of a modified form of hPMCA1b. In platelets, no evidence of the expression of hPMCA1b could be found. The amount of PMCA in these cells was compared with that of the constitutive form of the sarco/endoplasmic reticulum Ca2+ pump in non-muscle cells (SERCA2b) and also with the amount of PMCA in human erythrocytes. A very low level of the plasma membrane Ca2+ pump was found in platelets while in their precursor cells the expression of this Ca2+ pump was much more abundant. Whereas the expression level of PMCA decreased dramatically in mature human platelets, the expression of SERCA2b did not change substantially upon megakaryocytic differentiation.


Subject(s)
Blood Platelets/physiology , Calcium-Transporting ATPases/metabolism , Megakaryocytes/enzymology , Animals , Antibodies, Monoclonal , COS Cells/metabolism , Calcium-Transporting ATPases/immunology , Cation Transport Proteins , Cell Line , Erythrocytes/enzymology , Humans , Isoenzymes , Plasma Membrane Calcium-Transporting ATPases , Sensitivity and Specificity
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