scholarly journals Synthesis and secretion of alkaline phosphatase in vitro from first-trimester and term human placentas

1981 ◽  
Vol 194 (3) ◽  
pp. 857-866 ◽  
Author(s):  
H Galski ◽  
S E Fridovich ◽  
D Weinstein ◽  
N De Groot ◽  
S Segal ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Time Course ◽  
De Novo ◽  
Placental Tissue ◽  
First Trimester ◽  
Alkaline Phosphatases ◽  
Heat Stable ◽  
Alkaline Phosphatase Isoenzymes ◽  
Specific Activities

The synthesis and secretion of alkaline phosphatases in vitro by human placental tissue incubated in organ culture were studied. First-trimester placenta synthesizes and secretes two different alkaline phosphatase isoenzymes (heat-labile and heat-stable), whereas in term placenta nearly all the alkaline phosphatase synthesized and secreted is heat-stable. The specific activities of alkaline phosphatases in first-trimester and term placental tissue remain constant throughout the time course of incubation. In the media, specific activities increase with time. Hence, alkaline phosphatase synthesis seems to be the driving force for its own secretion. The rates of synthesis de novo and of alkaline phosphatases were measured. The specific radioactivities of the secreted alkaline phosphatases were higher than the corresponding specific radioactivities in the tissue throughout the entire incubation period. The intracellular distribution of the alkaline phosphatase isoenzymes was compared.

Alkaline phosphatase. I. Kinetics and inhibition by levamisole of purified isoenzymes from humans.

1976 ◽  
Vol 22 (7) ◽  
pp. 972-976 ◽  
Author(s):  
H Van Belle
Keyword(s):  
Alkaline Phosphatase ◽  
Substrate Concentration ◽  
Human Liver ◽  
Alkaline Phosphatases ◽  
Mechanism Of Inhibition ◽  
Optimum Ph ◽  
Alkaline Phosphatase Isoenzymes

Abstract I studied the kinetics and sensitivity toward inhibition by levamisole and R 8231 of the most important human alkaline phosphatase isoenzymes. N-Ethylaminoethanol proved superior to the now widely used diethanolamine buffer, especially for the enzymes from the intestine and placenta, behaving as an uncompetitive activator. The optimum pH largely depends on the substrate concentration. The addition of Mg2+ has no effect on the activities. The meaning of Km-values for alkaline phosphatases is questioned. Isoenzymes from human liver, bone, kidney, and spleen are strongly inhibited by levamisole or R 8231 at concentrations that barely affect the enzymes from intestine or placenta. The inhibition is stereospecific, uncompetitive, and not changed by Mg2+. Inhibition is counteracted by increasing concentrations of N-ethylaminoethanol. The mechanism of inhibition is suggested to be formation of a complex with the phosphoenzyme.

Alkaline phosphatase isoenzymes.

1982 ◽  
Vol 28 (10) ◽  
pp. 2007-2016 ◽  
Author(s):  
D W Moss
Keyword(s):  
Alkaline Phosphatase ◽  
Quantitative Analysis ◽  
Posttranslational Modifications ◽  
Quantitative Methods ◽  
Molecular Forms ◽  
Future Research ◽  
Alkaline Phosphatases ◽  
Isoenzyme Analysis ◽  
Alkaline Phosphatase Isoenzymes ◽  
Alkaline Phosphatase Isoenzyme

Abstract The human alkaline phosphatases constitute a system of multiple molecular forms of enzymes in which heterogeneity is partly due to genetic factors and partly to posttranslational modifications. Recognition of the nature and occurrence of these multiple forms has made a significant contribution both to the understanding of changes in alkaline phosphatase values for serum in disease and to the use of alkaline phosphatase measurements in diagnosis. Many of the diagnostic advantages of alkaline phosphatase isoenzyme analysis can be obtained with the aid of qualitative methods such as zone electrophoresis. However, quantitative methods are needed to take full advantage of the potential benefits of isoenzyme analysis. Selective inactivation methods can be applied successfully to the quantitative analysis of bone and liver alkaline phosphatases in serum. However, the aim of future research should be to remove the limitations at present imposed on quantitative analysis by the close similarities of bone and liver alkaline phosphatases.

The in vitro synthesis and secretion of alkaline phosphatase from first trimester human decidua

1982 ◽  
Vol 14 (1) ◽  
pp. 1-11 ◽  
Author(s):  
H. Galski ◽  
D. Weinstein ◽  
K. Abraham ◽  
N. de Groot ◽  
S. Segal ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
First Trimester ◽  
In Vitro Synthesis ◽  
Human Decidua

scholarly journals Activation of Peroxisome Proliferator-Activated Receptor Gamma by Human Cytomegalovirus for De Novo Replication Impairs Migration and Invasiveness of Cytotrophoblasts from Early Placentas

2009 ◽  
Vol 84 (6) ◽  
pp. 2946-2954 ◽  
Author(s):  
Benjamin Rauwel ◽  
Bernard Mariamé ◽  
Hélène Martin ◽  
Ronni Nielsen ◽  
Sophie Allart ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
De Novo ◽  
Present Report ◽  
Primary Cultures ◽  
First Trimester ◽  
Peroxisome Proliferator ◽  
Mobility Shift ◽  
Peroxisome Proliferator Activated Receptor ◽  
Human Trophoblast

ABSTRACT Human cytomegalovirus (HCMV) contributes to pathogenic processes in immunosuppressed individuals, in fetuses, and in neonates. In the present report, by using reporter gene activation assays and confocal microscopy in the presence of a specific antagonist, we show for the first time that HCMV infection induces peroxisome proliferator-activated receptor gamma (PPARγ) transcriptional activity in infected cells. We demonstrate that the PPARγ antagonist dramatically impairs virus production and that the major immediate-early promoter contains PPAR response elements able to bind PPARγ, as assessed by electrophoretic mobility shift and chromatin immunoprecipitation assays. Due to the key role of PPARγ in placentation and its specific trophoblast expression within the human placenta, we then provided evidence that by activating PPARγ human cytomegalovirus dramatically impaired early human trophoblast migration and invasiveness, as assessed by using well-established in vitro models of invasive trophoblast, i.e., primary cultures of extravillous cytotrophoblasts (EVCT) isolated from first-trimester placentas and the EVCT-derived cell line HIPEC. Our data provide new clues to explain how early infection during pregnancy could impair implantation and placentation and therefore embryonic development.

scholarly journals Simultaneous autoradiographic and histochemical analysis of bone formed in vitro.

1986 ◽  
Vol 34 (6) ◽  
pp. 769-773 ◽  
Author(s):  
H C Tenenbaum ◽  
C A McCulloch ◽  
K Palangio
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Time Course ◽  
Bone Cell ◽  
Histochemical Demonstration ◽  
Thymidine Uptake ◽  
Kinetics In Vivo

The simultaneous histochemical demonstration of alkaline phosphatase activity and autoradiographic demonstration of [3H]-thymidine uptake is valuable for study of bone cell kinetics in vivo or in vitro. By use of this technique, it has been possible to detect changes induced by a single dose of dexamethasone (10(-7) M) in the time course of alkaline phosphatase activity, the number of alkaline phosphatase-positive cells, and [3H]-thymidine labeling in bone formed in vitro.

scholarly journals Functional and Pharmacological Evaluation of a Novel SCN2A Variant Linked to Early-onset Epilepsy

2020 ◽  
Author(s):  
Scott K. Adney ◽  
John J. Millichap ◽  
Jean-Marc DeKeyser ◽  
Tatiana Abramova ◽  
Christopher H. Thompson ◽  
...  
Keyword(s):  
Drug Response ◽  
Time Course ◽  
Voltage Dependence ◽  
De Novo ◽  
Patch Clamp Recording ◽  
Variants Of Unknown Significance ◽  
Whole Cell Patch Clamp ◽  
Genetic Features ◽  
Resurgent Current

ABSTRACTObjectiveWe identified a novel de novo SCN2A variant (M1879T) associated with infantile-onset epilepsy that responded dramatically to sodium channel blocker antiepileptic drugs. We analyzed the functional and pharmacological consequences of this variant to establish pathogenicity, and to correlate genotype with phenotype and clinical drug response.MethodsThe clinical and genetic features of an infant boy with epilepsy are presented. We investigated the effect of the variant using heterologously expressed recombinant human NaV1.2 channels. We performed whole-cell patch clamp recording to determine the functional consequences and response to carbamazepine.ResultsThe M1879T variant caused disturbances in channel inactivation including substantially depolarized voltage-dependence of inactivation, slower time course of inactivation, and enhanced resurgent current that collectively represent a gain-of-function. Carbamazepine partially normalized the voltage-dependence of inactivation and produced use-dependent block of the variant channel at high pulsing frequencies. Carbamazepine also suppresses resurgent current conducted by M1879T channels, but this effect was explained primarily by reducing the peak transient current. Molecular modeling suggests that the M1879T variant disrupts contacts with nearby residues in the C-terminal domain of the channel.InterpretationOur study demonstrates the value of conducting functional analyses of SCN2A variants of unknown significance to establish pathogenicity and genotype-phenotype correlations. We also show concordance of in vitro pharmacology using heterologous cells with the drug response observed clinically in a case of SCN2A-associated epilepsy.

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