scholarly journals Bisphenol A Activates Calcium Influx in Immortalized GnRH Neurons

2019 ◽  
Vol 20 (9) ◽  
pp. 2160 ◽  
Author(s):  
Federico Alessandro Ruffinatti ◽  
Alessandra Gilardino ◽  
Valter Secchi ◽  
Erika Cottone ◽  
Davide Lovisolo ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Calcium Influx ◽  
Minor Effect ◽  
Biologically Relevant ◽  
Signaling Mechanisms ◽  
Neuroendocrine Axis ◽  
A Minor ◽  
The Impact ◽  
Plastic Containers

Bisphenol A (BPA) is one of the most widely used chemicals worldwide, e.g., as a component of plastic containers for food and water. It is considered to exert an estrogenic effect, by mimicking estradiol (E2) action. Because of this widespread presence, it has attracted the interest and concern of researchers and regulators. Despite the vast amount of related literature, the potential adverse effects of environmentally significant doses of BPA are still object of controversy, and the mechanisms by which it can perturb endocrine functions, and particularly the neuroendocrine axis, are not adequately understood. One of the ways by which endocrine disruptors (EDCs) can exert their effects is the perturbation of calcium signaling mechanisms. In this study, we addressed the issue of the impact of BPA on the neuroendocrine system with an in vitro approach, using a consolidated model of immortalized Gonadotropin-Releasing Hormone (GnRH) expressing neurons, the GT1–7 cell line, focusing on the calcium signals activated by the endocrine disruptor. The investigation was limited to biologically relevant doses (nM–µM range). We found that BPA induced moderate increases in intracellular calcium concentration, comparable with those induced by nanomolar doses of E2, without affecting cell survival and with only a minor effect on proliferation.

scholarly journals Differential effects of corticosteroids and anti-TNF on tumor-specific immune responses - implications for the management of irAEs

2018 ◽  
Author(s):  
Arianna Draghi ◽  
Troels Holz Borch ◽  
Haja Dominike Radic ◽  
Christopher Aled Chamberlain ◽  
Aishwarya Gokuldass ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Cell Activation ◽  
Tumor Infiltrating Lymphocytes ◽  
High Dose ◽  
Minor Effect ◽  
Tumor Killing ◽  
High Doses ◽  
A Minor ◽  
The Impact

AbstractUp to 60% of patients treated with cancer immunotherapy develop severe or life threatening immune-related adverse events (irAEs). Immunosuppression with high doses of corticosteroids or, in refractory cases, with tumor necrosis factor (TNF) antagonists, are the mainstay of treatment for irAEs. It is currently unknown what is the impact of corticosteroids and anti-TNF on the activity of antitumor T cells. In this study, the influences of clinically relevant doses of dexamethasone (corresponding to an oral dose of 10 to 125 mg prednisolone) and infliximab (anti-TNF) on the activation and killing ability of tumor-infiltrating lymphocytes (TILs) was tested in vitro. Overall, dexamethasone at low or intermediate/high dose impaired the activation (respectively −46% and −62%) and tumor-killing ability (respectively −48% and −53%) of tumor-specific TILs. In contrast, a standard clinical dose of infliximab only had a minor effect on T cell activation (−20%) and tumor killing (−10%). A brief resting following exposure to dexamethasone was sufficient to rescue the in vitro activity of TILs. In conclusion, clinically-relevant doses of infliximab only influenced to a lesser extent the activity of tumor-specific TILs in vitro, whereas even low doses of corticosteroids markedly impaired the antitumor activity of TILs. These data support steroid-sparing strategies and early initiation of anti-TNF for the treatment of irAEs in immuno-oncology.

scholarly journals A sand fly salivary protein acts as a neutrophil chemoattractant

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Calcium Influx ◽  
Parasite Burden ◽  
Salivary Protein ◽  
Sand Fly ◽  
Human Neutrophils ◽  
Chemotactic Protein ◽  
The Impact

AbstractApart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

scholarly journals Roles of Transcription Factor Mot3 and Chromatin in Repression of the Hypoxic Gene ANB1 in Yeast

2000 ◽  
Vol 20 (19) ◽  
pp. 7088-7098 ◽  
Author(s):  
Alexander J. Kastaniotis ◽  
Thomas A. Mennella ◽  
Christian Konrad ◽  
Ana M. Rodriguez Torres ◽  
Richard S. Zitomer
Keyword(s):  
Binding Site ◽  
Regulatory Region ◽  
Direct Interaction ◽  
Minor Effect ◽  
Histone H4 ◽  
Coding Region ◽  
Basal Transcriptional Machinery ◽  
In The Wild ◽  
A Minor

ABSTRACT The hypoxic genes of Saccharomyces cerevisiae are repressed by a complex consisting of the aerobically expressed, sequence-specific DNA-binding protein Rox1 and the Tup1-Ssn6 general repressors. The regulatory region of one well-studied hypoxic gene,ANB1, is comprised of two operators, OpA and OpB, each of which has two strong Rox1 binding sites, yet OpA represses transcription almost 10 times more effectively than OpB. We show here that this difference is due to the presence of a Mot3 binding site in OpA. Mutations in this site reduced OpA repression to OpB levels, and the addition of a Mot3 binding site to OpB enhanced repression. Deletion of the mot3 gene also resulted in reduced repression of ANB1. Repression of two other hypoxic genes in which Mot3 sites were associated with Rox1 sites was reduced in the deletion strain, but other hypoxic genes were unaffected. In addition, the mot3Δ mutation caused a partial derepression of the Mig1–Tup1-Ssn6-repressed SUC2 gene, but not the α2–Mcm1–Tup1-Ssn6-repressed STE2 gene. The Mot3 protein was demonstrated to bind to the ANB1 OpA in vitro. Competition experiments indicated that there was no interaction between Rox1 and Mot3, indicating that Mot3 functions either in Tup1-Ssn6 recruitment or directly in repression. A great deal of evidence has accumulated suggesting that the Tup1-Ssn6 complex represses transcription through both nucleosome positioning and a direct interaction with the basal transcriptional machinery. We demonstrate here that under repressed conditions a nucleosome is positioned over the TATA box in the wild-type ANB1promoter. This nucleosome was absent in cells carrying arox1, tup1, or mot3 deletion, all of which cause some degree of derepression. Interestingly, however, this positioned nucleosome was also lost in a cell carrying a deletion of the N-terminal coding region of histone H4, yet ANB1expression remained fully repressed. A similar deletion in the gene for histone H3, which had no effect on repression, had only a minor effect on the positioned nucleosome. These results indicate that the nucleosome phasing on the ANB1 promoter caused by the Rox1–Mot3–Tup1-Ssn6 complex is either completely redundant with a chromatin-independent repression mechanism or, less likely, plays no role in repression at all.

scholarly journals Neurokinin B regulates reproduction via inhibition of kisspeptin in a teleost, the striped bass

2017 ◽  
Vol 233 (2) ◽  
pp. 159-174 ◽  
Author(s):  
Nilli Zmora ◽  
Ten-Tsao Wong ◽  
John Stubblefield ◽  
Berta Levavi-Sivan ◽  
Yonathan Zohar
Keyword(s):  
Striped Bass ◽  
Brain Slices ◽  
Neuronal Population ◽  
Minor Effect ◽  
Pituitary Cells ◽  
Neurokinin B ◽  
A Minor ◽  
Lh Secretion

Kisspeptin and neurokinin B (NKB) are neuropeptides co-expressed in the mammalian hypothalamus and coordinately control GnRH signaling. We have found that Nkb and kisspeptin neurons are distinct in the teleost, striped bass (STB) and capitalized on this phenomenon to study the mode of action of Nkb and its related neuropeptide-F (Nkf), both of which are encoded by the tac3 gene. In vitro brain slices and in vivo administration studies revealed that Nkb/f consistently downregulated kiss2, whereas antagonist (AntD) administration restored this effect. Overall, a minor effect was noted on gnrh1 expression, whereas Gnrh1 content in the pituitaries was reduced after Nkb/f treatment and increased with AntD. Concomitantly, immunostaining demonstrated that hypothalamic Nkb neurons border and densely innervate the largest kiss2 neuronal population in the hypothalamus, which also coexpresses Nkb receptor. No expression of Nkb receptor or Nkb neuronal projections was detected near/in Gnrh1 soma in the preoptic area. At the level of the pituitary, however, the picture was more complex: both Nkb/f and AntD upregulated lhb and fshb expression and Lh secretion in vivo. Together with the stimulatory effect of Nkb/f on Lh/Fsh secretion from pituitary cells, in vitro, this may indicate an additional independent action of Nkb/f within the pituitary, in which the hypothalamic pathway is more dominant. The current study demonstrates that Nkb/f utilizes multiple pathways to regulate reproduction in the STB and that in the brain, Nkb mainly acts as a negative modulator of kiss2 to regulate the release of Gnrh1.

scholarly journals U2 small nuclear RNA 3' end formation is directed by a critical internal structure distinct from the processing site.

1993 ◽  
Vol 13 (2) ◽  
pp. 1119-1129 ◽  
Author(s):  
M R Jacobson ◽  
M Rhoadhouse ◽  
T Pederson
Keyword(s):  
Rna Processing ◽  
Minor Effect ◽  
Small Nuclear Rna ◽  
Recognition Sequence ◽  
Stem Loop ◽  
Branch Site ◽  
Nuclear Rna ◽  
A Minor ◽  
Site Recognition

Mature U2 small nuclear RNA is generated by the removal of 11 to 12 nucleotides from the 3' end of the primary transcript. This pre-U2 RNA processing reaction takes place in the cytoplasm. In this study, the sequences and/or structures of pre-U2 RNA that are important for 3' processing have been examined in an in vitro system. The 7-methylguanosine cap, stem-loops I and II, the lariat branch site recognition sequence, the conserved Sm domain, and several other regions throughout the 5' end of U2 RNA have no apparent role in the 3' processing reaction. In fact, deletion of the entire first 104 nucleotides resulted in mini-pre-U2 RNAs which were efficiently processed. Similarly, deletion of the top two-thirds of stem-loop III or mutation of nucleotides in the loop of stem-loop IV had little effect on 3' processing. Most surprisingly, the precursor's 11- to 12-nucleotide 3' extension itself was of relatively little importance, since this sequence could be replaced with completely different sequences with only a minor effect on the 3' processing reaction. In contrast, we have defined a critical structure consisting of the bottom of stem III and the stem of stem-loop IV that is essential for 3' processing of pre-U2 RNA. Compensatory mutations which restore base pairing in this region resulted in normal 3' processing. Thus, although the U2 RNA processing activity recognizes the bottom of stem III and stem IV, the sequence of this critical region is much less important than its structure. These results, together with the surprising observation that the reaction is relatively indifferent to the sequence of the 11- to 12-nucleotide 3' extension itself, point to a 3' processing reaction of pre-U2 RNA that has sequence and structure requirements significantly different from those previously identified for pre-mRNA 3' processing.

scholarly journals Epigenetic effects of Bisphenol A on granulosa cells of mouse follicles during in vitro culture: An experimental study

2021 ◽  
Author(s):  
Aylin Jamali Khaghani ◽  
Parisa Farrokh ◽  
Saeed Zavareh
Keyword(s):  
Bisphenol A ◽  
Granulosa Cells ◽  
Promoter Methylation ◽  
Inhibitory Effect ◽  
Promoter Regions ◽  
Endocrine Disrupting Chemical ◽  
Epigenetic Effects ◽  
Endocrine Disrupting ◽  
The Impact

Background: Bisphenol A (BPA), a synthetic endocrine-disrupting chemical, is a reproductive toxicant. Granulosa cells have significant roles in follicle development, and KIT ligand (KITL) and Anti-Müllerian hormone (AMH) are essential biomolecules produced by them during folliculogenesis. Objective: Due to the widespread use of BPA and its potential epigenetic effects, this study examined the impact of BPA on promoter methylation of amh and kitl genes in mouse granulosa cells. Materials and Methods: Preantral follicles were isolated from ovaries of immature mice and cultured for eight days. Then, follicles were treated with 50 and 100 μM of BPA, and 0.01% (v/v) ethanol for 24 and 72 hr. Growth and degeneration of follicles and antrum formation were analyzed. The granulosa cells were isolated mechanically, and their extracted DNA was treated with sodium bisulfite. The promoter regions of the amh and kitl were analyzed with PCR and sequencing. Results: BPA did not change follicle survival and antrum formation significantly (p = 0.41). However, the culture in the presence of 100 μM BPA had an inhibitory effect on growth. Before BPA treatment, the CpG of the kitl and amh promoters were unmethylated and partially methylated, respectively. While the percent of 5mC in the amh promoter reduced at 100 μM of BPA, it did not alter the kitl promoter methylation. Conclusion: BPA at higher concentrations has an inhibitory effect on follicle growth. Moreover, it seems that the epigenetic impact of BPA restricts to the demethylation of CpG sites. Key words: Bisphenol A, DNA methylation, Granulosa cells.

Isothermal Physical Flow Modeling of a Gas Turbine Simple-Cycle Selective-Catalytic-Reduction (SCR) System

2013 ◽  
Author(s):  
Larry Swanson ◽  
Hua Zhang ◽  
Doug Byrd
Keyword(s):  
Selective Catalytic Reduction ◽  
Gas Turbine ◽  
Catalytic Reduction ◽  
Transport Processes ◽  
Simple Cycle ◽  
Minor Effect ◽  
Tracer Injection ◽  
A Minor ◽  
Scr System ◽  
The Impact

A physical flow model of a gas turbine (GT) simple-cycle Selective-Catalytic-Reduction (SCR) system was constructed to a 1/16 geometric scale to validate computational fluid dynamics (CFD) predictions and examine the impact of tempering air injection on system performance. Repeatable velocity contours and tempering air dispersion profiles were developed for baseline (no tempering air), and 12- and 6-lance tempering air injector configurations. The conclusions from the study are: (1) relative to the no lance baseline case, the 12-lance configuration tends to force more of the inlet flow towards the top of the duct, whereas the 6-lance configuration does not affect the upstream profile significantly, (2) adding tempering air does not have a significant impact on the diffuser inlet velocity distribution and has a minor effect on the velocity and dispersion profiles at the NOX-catalyst inlet, (3) at the NOX-catalyst inlet, the 6-lance configuration with tempering air exhibits a slightly skewed flow toward the lower right corner of the duct with a coefficient of variation (COV) of 19.4%, which is slightly better than that for the 12-lance configuration, (4) at the NOX-catalyst inlet, the 12-lance configuration disperses tempering air best because its COV is 20.8% relative to a 27.3% COV for the 6-lance configuration, and (5) a comparison between the local mixing-cup temperature contours for both 12- and 6-lance configurations, based on tracer injection into the tempering air flow, confirms that the CFD model does a good job of qualitatively predicting the heat and mass transport processes in the GT simple-cycle SCR system.

DN.9693 COMPARED WITH PROSTACYCLIN AND PROSTAGLANDIN E1 IN SEVEN PLATELET TESTS

1987 ◽  
Author(s):  
J R O'Brien ◽  
M D Etherington ◽  
G P Salmon
Keyword(s):  
Bleeding Time ◽  
Prostaglandin E ◽  
Minor Effect ◽  
Membrane Glycoproteins ◽  
Clot Retraction ◽  
Platelet Factor ◽  
Active Concentration ◽  
A Minor ◽  
Induced Aggregation

A new drug, DN.9693, has low Km phosphodiesterase inhibitory properties. Its effect on seven broad spectrum platelet "function" tests has been compared with the effects of prostacyclin E1 (PGI1) and prostaglandin E (PGE ). The tests were (1) platelet aggregation induced by ADP, collagen, adrenaline, thrombin, arachidonic acid and ristocetin; (2) a new test in which platelets aggregate after adding distilled water to cause osmotic stress; (3) the loss of platelets washed in buffered saline; (4) clot retraction; (5) the glass bead column platelet retention test; (6) the in vitro filter "bleeding time" (see two other submitted abstracts); (7) the amount of platelet factor 4 (PF4) which "leaks" from platelets at room temperature.PGI2 inhibited all seven tests, 50% inhibition of the various tests required from 0.1 to 44ng/ml of PGI2. PGE1 also inhibited in all tests but on average required 18 times higher concentrations. Thus an increase in cAMP may be relevant to all these tests, but an understanding of the mechanisms involved is incomplete. DN.9693 inhibited only the first four tests; the equi-active concentration was about 600 times that of PGI2. DN.9693, 2.5μg/ml, caused 50% inhibition of ristocetin induced aggregation and at 4μg/ml had a minor effect on the filter bleeding time. Thus DN.9693 may affect the platelet membrane glycoproteins. In conclusion it is confirmed that PGE1 is less active than PGI^ but has similar activities. DN.9693 whenstudied in these tests has many, but notall, of the prostaglandin-like properties.

scholarly journals Are suggestions from coupled file changes useful for perfective maintenance tasks?

2017 ◽  
Vol 3 ◽  
pp. e135 ◽  
Author(s):  
Jasmin Ramadani ◽  
Stefan Wagner
Keyword(s):  
Software Maintenance ◽  
Tracking System ◽  
Minor Effect ◽  
New Members ◽  
Team Members ◽  
Using Data ◽  
Time Required ◽  
A Minor ◽  
The Impact ◽  
Important Activity

Background Software maintenance is an important activity in the development process where maintenance team members leave and new members join over time. The identification of files which are changed together frequently has been proposed several times. Yet, existing studies about coupled file changes ignore the feedback from developers as well as the impact of these changes on the performance of maintenance and rather these studies rely on the analysis findings and expert evaluation. Methods We investigate the usefulness of coupled file changes during perfective maintenance tasks when developers are inexperienced in programming or when they were new on the project. Using data mining on software repositories we identify files that are changed most frequently together in the past. We extract coupled file changes from the Git repository of a Java software system and join them with corresponding attributes from the versioning and issue tracking system and the project documentation. We present a controlled experiment involving 36 student participants in which we investigate if coupled file change suggestions influence the correctness of the task solutions and the required time to complete them. Results The results show that the use of coupled file change suggestions significantly increases the correctness of the solutions. However, there is only a minor effect on the time required to complete the perfective maintenance tasks. We also derived a set of the most useful attributes based on the developers’ feedback. Discussion Coupled file changes and a limited number of the proposed attributes are useful for inexperienced developers working on perfective maintenance tasks where although the developers using these suggestions solved more tasks, they still need time to understand and organize this information.

U2 small nuclear RNA 3' end formation is directed by a critical internal structure distinct from the processing site

1993 ◽  
Vol 13 (2) ◽  
pp. 1119-1129
Author(s):  
M R Jacobson ◽  
M Rhoadhouse ◽  
T Pederson
Keyword(s):  
Rna Processing ◽  
Minor Effect ◽  
Small Nuclear Rna ◽  
Recognition Sequence ◽  
Stem Loop ◽  
Branch Site ◽  
Nuclear Rna ◽  
A Minor ◽  
Site Recognition

Mature U2 small nuclear RNA is generated by the removal of 11 to 12 nucleotides from the 3' end of the primary transcript. This pre-U2 RNA processing reaction takes place in the cytoplasm. In this study, the sequences and/or structures of pre-U2 RNA that are important for 3' processing have been examined in an in vitro system. The 7-methylguanosine cap, stem-loops I and II, the lariat branch site recognition sequence, the conserved Sm domain, and several other regions throughout the 5' end of U2 RNA have no apparent role in the 3' processing reaction. In fact, deletion of the entire first 104 nucleotides resulted in mini-pre-U2 RNAs which were efficiently processed. Similarly, deletion of the top two-thirds of stem-loop III or mutation of nucleotides in the loop of stem-loop IV had little effect on 3' processing. Most surprisingly, the precursor's 11- to 12-nucleotide 3' extension itself was of relatively little importance, since this sequence could be replaced with completely different sequences with only a minor effect on the 3' processing reaction. In contrast, we have defined a critical structure consisting of the bottom of stem III and the stem of stem-loop IV that is essential for 3' processing of pre-U2 RNA. Compensatory mutations which restore base pairing in this region resulted in normal 3' processing. Thus, although the U2 RNA processing activity recognizes the bottom of stem III and stem IV, the sequence of this critical region is much less important than its structure. These results, together with the surprising observation that the reaction is relatively indifferent to the sequence of the 11- to 12-nucleotide 3' extension itself, point to a 3' processing reaction of pre-U2 RNA that has sequence and structure requirements significantly different from those previously identified for pre-mRNA 3' processing.

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