scholarly journals Effects of a complex mixture of persistent organic pollutants (POPs) on steroidogenesis in H295R cells under 10 μM forskolin stimulation - results from a pilot study

2018 ◽  
Author(s):  
Kareem Eldin Mohammed Ahmed ◽  
Håvard G Frøysa ◽  
Odd André Karlsen ◽  
Karin Elisabeth Zimmer ◽  
Hanne Friis Berntsen ◽  
...  
Keyword(s):  
Pilot Study ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Complex Mixture ◽  
The Other ◽  
Exposure Concentration ◽  
Down Regulation ◽  
Low Concentration ◽  
Other Hand ◽  
H295r Cells

AbstractThis study describes the utilization of an LC-MS/MS based H295R assay to assess an environmentally relevant mixture of persistent organic pollutants (POPs). H295R cells were exposed to the POP mixture in two conditions stimulated with 10 μM forskolin and unstimulated. Most importantly, the unstimulated cells responded to the low concentration of the mixture with a significant down-regulation of dehydroepiandrosterone (DHEA). This response was not observed in forskolin-stimulated cells. In stimulated H295R cells, exposure to the highest concentration showed a trend towards induced production of mineralocorticoids and glucocorticoids, although this was not significant. On the other hand, in the same exposure concentration and condition, estrogen and androgen production tended to be down-regulated. In addition to these patterns of responses being different in the stimulated vs unstimulated condition, four steroids were not detectable in the unstimulated condition.

scholarly journals Decreased ligand affinity rather than glucocorticoid receptor down-regulation in patients with endogenous Cushing's syndrome

2000 ◽  
pp. 472-476 ◽  
Author(s):  
NA Huizenga ◽  
WW De Herder ◽  
JW Koper ◽  
P de Lange ◽  
D AJ v Lely ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Cushing’S Syndrome ◽  
Cushing's Syndrome ◽  
The Body ◽  
The Other ◽  
Down Regulation ◽  
Ligand Affinity ◽  
Other Hand ◽  
Receptor Number ◽  
Cortisol Levels

OBJECTIVE: Glucocorticoids (GCs) serve a variety of important functions throughout the body. The synthesis and secretion of GCs are under the strict influence of the hypothalamo-pituitary-adrenal axis. The mechanisms of action of GCs are mediated by the intracellular glucocorticoid receptor (GR). Over the years, many studies have been performed concerning the regulation of GR expression by GC concentrations. METHODS: In the present study, we determined the characteristics of the GR in peripheral mononuclear blood leukocytes (PBML) from thirteen patients with endogenous Cushing's syndrome and fifteen control subjects, using a whole cell dexamethasone binding assay. Furthermore, cortisol concentrations were determined in order to investigate a possible relationship between serum cortisol levels and receptor characteristics. RESULTS: There were no differences in mean receptor number between patients and controls. On the other hand, a significantly lower ligand affinity was identified in cells from patients with Cushing's syndrome compared with controls. A complete normalisation of the ligand affinity was observed after treatment in the only patient tested in this respect, whereas the receptor number was not affected. In patients, there was a statistically significant negative correlation between cortisol concentrations and ligand affinity, which was not found in controls. CONCLUSION: Receptor down-regulation does not occur in PBML from patients with endogenous Cushing's syndrome. On the other hand, there seems to be a diminished ligand affinity which possibly reflects receptor modification in response to exposure to the continuously high cortisol levels in patients with Cushing's syndrome. This assumption is substantiated by the fact that in one patient a normalisation of the ligand affinity after complete remission of the disease was seen.

scholarly journals Dispersal of persistent organic pollutants from fiber-contaminated sediments: biotic and abiotic pathways

2021 ◽  
Author(s):  
Anna-Karin Dahlberg ◽  
Anna Apler ◽  
Paul Frogner-Kockum ◽  
Gunnel Göransson ◽  
Ian Snowball ◽  
...  
Keyword(s):  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
River Estuary ◽  
Contaminated Sediments ◽  
The Body ◽  
Passive Samplers ◽  
The Other ◽  
Sediment Surface ◽  
Average Particle ◽  
Particle Resuspension

Abstract Purpose Numerous sites contaminated with fiber emissions from pulp and paper industries are found in coastal areas of the Baltic Sea, but there is limited knowledge about the magnitude of dispersal of persistent organic pollutants (POPs) from these anthropogenic, organic-rich sediments called fiberbanks. The aim of this study was to quantify and compare different POP dispersal pathways from such fiberbanks. Dispersal mechanisms studied included abiotic and biotic routes (dissolved in water, particle-bound, and bioaccumulation). Materials and methods Contaminated fibrous sediments located in Ångermanälven River estuary in north-eastern Sweden were studied in sediment types representing different fiber content (i.e., fiberbanks, fiber-rich sediments, and less fiber impacted sediments). Sediment-to-water fluxes of dissolved contaminants (polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT)) were measured in situ using benthic flux chambers. Particle resuspension was measured by sampling bottom water, before and after disturbing the sediment surface. Benthic biota was collected to determine the body burden of contaminants and to determine biota-pore water accumulation factors (BAFPW) and biota-sediment accumulation factors (BSAFs). In addition, concentrations of dissolved POPs in the water column were measured in field using passive samplers. Instrumental analysis was performed using gas chromatography coupled to a triple quadrupole mass spectrometer (GC-MS/MS). Results and discussion The flux of dissolved Σ20PCBs was approximately two times higher from one of the investigated fiberbanks (3.4 ng m− 2 day− 1) compared to the other. The average particle burden of PCBs was also higher at this fiberbank after artificial disturbance (15 ng g−1 particle), which indicates that larger amounts of contaminants are likely to disperse via particle resuspension from this site compared to the other fiberbank (4.8 ng g− 1 particle). The difference might be associated with a layer of recently settled minerogenic material that covers one of the fiberbanks, which probably functions as a protective barrier. The lack of benthic biota implies that contaminant release by bioturbation is negligible in the studied fiberbanks. However, benthic biota from fiber-rich sediment showed bioaccumulation and biomagnification of contaminants. Conclusions The importance of diffusive flux from fiberbanks under undisturbed conditions became apparent when the different dispersal pathways were quantified. However, no dispersal pathway could be judged as irrelevant, since even under undisturbed conditions, advective particle transport was significant. Additionally, the uptake by biota and trophic transfer can be considerable. Quantification of dispersal routes and understanding of the relative importance of various pathways is critical for proper risk assessment and management of contaminated sediments.

scholarly journals A Human Relevant Defined Mixture of Persistent Organic Pollutants (POPs) Affects In Vitro Secretion of Glucagon-Like Peptide 1 (GLP-1), but Does Not Affect Translocation of Its Receptor

2019 ◽  
Vol 172 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Maeve Shannon ◽  
Yuling Xie ◽  
Steven Verhaegen ◽  
Jodie Wilson ◽  
Hanne F Berntsen ◽  
...  
Keyword(s):  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Complex Mixture ◽  
Blood Levels ◽  
Environmental Toxicants ◽  
Blood Concentrations ◽  
Total Mixture ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Abstract Environmental exposure to persistent organic pollutants (POPs) has been suggested as a contributing factor for the increased rate of type 2 diabetes and obesity. A complex mixture of 29 POPs (Total mixture), based on human blood concentrations, was used to expose a glucagon-like peptide 1 (GLP-1) secreting enteroendocrine cell line (pGIP/neo: STC-1) in vitro for 3 and 24 h. Significant increases of GLP-1 occurred when cells were exposed to the Total mixture at ×500 blood levels. Six sub-mixtures representing chlorinated (Cl), brominated (Br), and perfluorinated chemicals (PFAA), and their combinations (Cl + Br, Cl + PFAA, Br + PFAA) were also tested at ×500. Secretion levels seen for these remained lower than the Total mixture, and the Br mixture had no effect. After 24 h, increased secretion was seen with all mixtures at ×1 blood levels. Cytotoxicity was present for ×100 and ×500 blood levels. When tested in a GLP-1 receptor translocation assay (U2OS-GLP1R-EGFP), neither agonistic nor antagonist effects on receptor internalization were seen for any of the mixtures. We conclude individual classes of POPs, alone or in combination, can affect GLP-1 secretion and may contribute as a molecular mechanism linking environmental toxicants and diabetes.

Global pilot study for persistent organic pollutants (POPs) using PUF disk passive air samplers

2006 ◽  
Vol 144 (2) ◽  
pp. 445-452 ◽  
Author(s):  
Tom Harner ◽  
Karla Pozo ◽  
Todd Gouin ◽  
Anne-Marie Macdonald ◽  
Hayley Hung ◽  
...  
Keyword(s):  
Pilot Study ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants

Novel Molecular Findings in Protein Tyrosine Phosphatase Receptor Gamma (PTPRG) Among Chronic Myelocytic Leukemia (CML) Patients Studied By Next Generation Sequencing (NGS): A Pilot Study in Patients from the State of Qatar and Italy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5427-5427 ◽  
Author(s):  
Nader I Al-Dewik ◽  
Maria Monne ◽  
Mohammed Araby ◽  
Ali Al Sayab ◽  
Marzia Vezzalini ◽  
...  
Keyword(s):  
Pilot Study ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Genetic Alterations ◽  
The Other ◽  
Chronic Myelocytic Leukemia ◽  
Protein Tyrosine ◽  
Myelocytic Leukemia ◽  
Other Hand

Abstract Background: Chronic Myelocytic Leukemia (CML) is a clonal myeloproliferative disorder characterized by constitutive phosphorylation of Protein Tyrosine kinases (PTKS) that continuously activates multiple proliferative and antiapoptotic signaling pathways. Protein Tyrosine Phosphatases (PTPs) on the other hand is potential natural inhibitory mechanism for regulating the tyrosine kinase activities in which phosphorylation is reciprocally controlled and maintained in equilibrium state by PTKs and PTPs. As a member of PTPs family, Protein Tyrosine Phosphatase Receptor Gamma (PTPRG) was found to act as a tumor suppressor gene. This negative regulatory mechanism of PTPRG was observed to be down-regulated and disabled in CML and one of the possible mechanisms that alter the negative regulatory effect of PTPs is mutations. Several mutations have been identified in PTPs in many different leukemias such as Acute Myeloid Leukemia (AML), Juvenile MyeloMonocytic Leukemia (JMML), Myelodysplasic Syndrome (MDS), B-cell Acute Lymphoblastic Leukemia (B-ALL) and these mutations are associated with hyper-cellular proliferation, disease progression and poor outcome. However, relatively little is known about PTPRG mutations and no studies on CML are available in the literature while mutations inBCR-ABL1tyrosine kinase have been extensively characterized. Thus, understanding the role of PTPRG in antagonizing the PTK phosphorylation of BCR-ABL1 will be important to determine its role in CML development and progression. Aim: 1) To identify potential genetic alterations causing inactivation of PTPRG and 2) correlate the PTPRG findings with patients' response to the Tyrosine kinase Inhibitors. Methods: 16 CML patients, 9 from Qatar and 7 from Italy respectively, were studied for PTPRG mutations by exome sequencing. Custom primers were designed for Human PTPRG gene (5 Kb of exonic region of interest) using Ion AmpliSeq Designer. Target regions were enriched and amplified for the 16 DNA samples using Ion AmpliSeq Library kit 2.0. The amplicons were partially digested with FuPa reagent and phosphorylated prior to ligation of Ion Xpress Barcode Adapters followed by cleanup using HighPrep reagent. The adapter ligated molecules were enriched with adapter specific primers using a limited cycle PCR followed by a cleanup using HighPrep reagent. The final libraries were quantified on Qubit Flurometer using Qubit dsDNA HS Assay Kit and Agilent Bioanalyzer using Agilent High Sensitivity DNA Kit. All samples were pooled according to the concentrations on the Bioanalyzer and loaded on Ion 318TM Chip kit V2 to be sequenced on Ion Personal Genome Machine (PGM) system. European Leukemia Net (ELN) 2013 criteria were employed to assess the response/resistance of patients to treatment. Responses are defined at the hematological, cytogenetic and molecular levels. Patients response was classified into optimal and failure Results: Four mutations/variants were identified in PTPRG genes, three were missense Y92H, G574S, S561Y and 1 was frameshift Y285fs in the 16 CML patients. PTPRG Y92H was identified in 5 (1 Homozygous and 4 heterozygous alleles) patients and the 5 patient failed the Imatinib Mesylate (IM) treatment. On the other hand, The PTPRG G574S was identified in 6 (2 homozygous and 4 heterozygous alleles) patients. Out of the 6 patients, 4 were classified as failure to the treatment and 2 responded optimally. In addition, the PTPRG S561Y and Y285fs were identified on 1 and 3 patients respectively and these patients responded optimally to IM treatment. Discussion and Conclusions: This is the first prospective pilot study to investigate PTPRG gene mutations as underlying mechanism to explain treatment failure. Our preliminary data showed that the identified variant PTPRG Y92H might be associated with IM failure although it has been reported as Single Nucleotide Polymorphisms (SNPs) (rs62620047) and this could be attributed that some polymorphisms might behave like a mutation. On the other hand, PTPRG G574S variant (rs2292245) showed various clinical outcomes regardless to its allele zygosity as 67% (4/6) of patients failed the TKIs treatment. From the results of our pilot study we recommend carrying out PTPRG sequencing in a significantly larger cohort of patients to further explore and pinpoint the crucial mutations that can be correlated with CML resistance/response to treatment. Disclosures No relevant conflicts of interest to declare.

Curcumin Prevents Cytokine-Mediated Tissue Factor Pathway Inhibitor Down-Regulation in Human Endothelial Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1202-1202
Author(s):  
Keiko Maruyama ◽  
Eriko Morishita ◽  
Yukie Goto ◽  
Akiko Sekiya ◽  
Hidesaku Asakura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Western Blotting ◽  
Tissue Factor Pathway Inhibitor ◽  
The Other ◽  
Tnf Alpha ◽  
Down Regulation ◽  
Protein Levels ◽  
Other Hand ◽  
Tissue Factor Pathway

Abstract Abstract 1202 Objective: Curcumin (diferuloyl methane), an active component of the spice turmeric, has been shown to exhibit anti-inflammatory and antioxidant activities in addition to an anticartinogenic activity in vitro and in vivo. Furthermore, we reported that curcumin inhibited the induction of tissue factor (TF) expression in human umbilical vein endothelial cells (HUVECs) at 52nd ASH 2010. Therefore, curcumin may ameliorate hyper-coagulable state associated with inflammation or oxidative stress. On the other hand, tissue factor pathway inhibitor (TFPI) which is expressed by endothelial cells plays a crucial role in hemostasis by regulating TF-induced initiation of coagulation. This study examined whether curcumin modulates the expression of TFPI in HUVECs. Methods: HUVECs were pretreated with curcumin at the concentration of 20 μM for 3h, washed and stimulated with tumor necrosis factor-alpha (TNF-alpha, 10 ng/ml) for additional 12 or 24h. The mRNA and protein levels of TFPI in the cultured HUVECs were determined by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting, respectively. To determine whether curcumin affects the MAPK signaling pathways, the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinase1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) in the HUVECs were analyzed with western blotting. Additionally, to determine whether curcumin affects nuclear factor-kappa B (NF-kB) pathway, nuclear and cytoplasmic fractions were extracted and protein levels were determined by western blotting for NF-kB (p65), p-IkB and IkB. Results: After TNF-alpha stimulation, TFPI mRNA levels were approximately decreased by 40% compared to the control (p<0.05; Figure 1B). Similarly to the mRNA expression, TFPI protein levels were decreased (Figure 1A). On the other hand, pretreatment of HUVECs with curcumin significantly suppresses TNF-alpha-induced TFPI mRNA and protein down-regulation (p<0.05; Figure 1A, B). Curcumin inhibited TNF-alpha-induced activation of p38MAPK, ERK1/2, and JNK. Moreover, curcumin inhibits TNF-alpha-induced IkB activation in HUVECs. And, translocation of NF-kB from the cytosol into the nucleus by TNF-alpha was inhibited by curcumin. Conclusions: These results indicate that curcumin may suppress the TNF-alpha-induced TFPI down-regulation via NF-kB pathways. Thus, curcumin may offer a novel antithrombotic option for treatment of the hypercoagulable state associated with inflammation. Disclosures: No relevant conflicts of interest to declare.

Inhibitory effects of calcium ionophore pretreatment of porcine oocytes on polyspermic fertilization

Zygote ◽  
2006 ◽  
Vol 14 (1) ◽  
pp. 17-22 ◽  
Author(s):  
T. Hayashi ◽  
H. Sato ◽  
H. Iwata ◽  
T. Kuwayama ◽  
Y. Monji
Keyword(s):  
Calcium Ionophore ◽  
Inhibitory Effect ◽  
Calcium Ionophore A23187 ◽  
The Other ◽  
Ionophore A23187 ◽  
Inhibitory Effects ◽  
High Concentration ◽  
Maturation Period ◽  
Low Concentration ◽  
Other Hand

The present study examined the inhibitory effects of various pretreatment concentrations (0–100 μM) of the calcium ionophore A23187 on polyspermic fertilization and then examined the effect of the maturation period and the time between calcium ionophore treatment and fertilization on the inhibitory effect of calcium ionophore on polyspermic fertilization. In experiment 1, a high concentration of calcium ionophore (100 μM) increased the rate of activated oocytes, but the rate of fertilization declined. On the other hand, when oocytes were treated with a low concentration of calcium ionophore (10 μM), monospermic fertilization was significantly increased (10 μM; 31.3%) (p < 0.05). In experiment 2, oocytes were cultured for various times (0, 0.5, 3, 6 h) after calcium ionophore treatment (10 μM) before fertilization. The highest rate of monospermic fertilization was detected in the oocytes cultured for 6 h after calcium ionophore treatment before fertilization. In experiments 3 and 4, we examined the effect of the maturation period (40 h or 44 h) on the rate of fertilization and blastulation of oocytes pretreated with calcium ionophore. The treatment of oocytes with calcium ionophore significantly decreased the rate of polyspermic fertilization regardless of the maturation period (44 h: with calcium ionophore 26.25% vs without 78.8%; 40 h: with calcium ionophore 37.5% vs without 77.5%); however, calcium ionophore treatment increased the rates of monospermic fertilization and blastulation of the oocytes matured for 44 h, but not those matured for 40 h. In conclusion, activation with a low concentration of calcium ionophore (10 μM) and a further 6 h of culture before fertilization improved the rate of monospermic fertilization and blastulation.

scholarly journals Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July–August 2001: a multi-analytical approach

2003 ◽  
Vol 3 (5) ◽  
pp. 1743-1757 ◽  
Author(s):  
J. Sciare ◽  
H. Cachier ◽  
K. Oikonomou ◽  
P. Ausset ◽  
R. Sarda-Estève ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Complex Mixture ◽  
Sea Salt ◽  
The Other ◽  
Total Carbon ◽  
The Black Sea ◽  
Thermal Method ◽  
Carbonaceous Aerosols ◽  
Temperature Program ◽  
Other Hand

Abstract. During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 mgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 mgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope=1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA's techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture. Spherical, smooth and silico-aluminated fly-ash observed by an Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A rough calculation based on a BC/nss-SO4 mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign. From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion.

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