Two Signal Transduction Pathways Involved in the Catecholaminergic Differentiation of Avian Neural Crest-Derived Cells In Vitro

2001 ◽  
Vol 18 (4) ◽  
pp. 394-406 ◽  
Author(s):  
Xiaodong Wu ◽  
Marthe J. Howard
1992 ◽  
Vol 263 (5) ◽  
pp. E943-E949 ◽  
Author(s):  
S. Y. Hsu ◽  
F. W. Goetz

The present study investigated the effects of a number of oxoanion compounds on in vitro ovulation of goldfish follicles and ovarian second messenger activities. Significant levels of ovulation were induced by 0.1 mM sodium chromate, 0.1 mM sodium metavanadate, 10 mM sodium molybdate, 0.1 mM sodium orthovanadate, 5 mM sodium selenate, 0.5 mM sodium tungstate, and 0.1 mM vanadyl sulfate. At levels that significantly stimulated ovulation, metavanadate, molybdate, orthovanadate, tungstate, and vanadyl sulfate also stimulated follicular phosphatidylinositol cycling and inhibited ovarian alkaline phosphatase activity. Moreover, the ovulation induced by these oxoanions was not inhibited by indomethacin (10 micrograms/ml), while ovulation induced by selenate and chromate was. In contrast, only vanadium-containing compounds significantly stimulated prostaglandin (PG) synthesis, and, in fact, selenate significantly inhibited PG production. Finally, only sodium molybdate- and vanadium-containing compounds appeared to increase follicular adenosine 3',5'-cyclic monophosphate content. While all oxoanions stimulated in vitro ovulation, they had differential effects on certain signal transduction pathways when tested at concentrations that stimulated in vitro ovulation. From the results, two basic groups could be delineated, one containing tungstate-, molybdate-, and vanadium-containing compounds and the other selenate and chromate. Thus the mechanism by which ovulation is induced by chromate and selenate may be different from that of vanadium-containing compounds, molybdate, and tungstate.(ABSTRACT TRUNCATED AT 250 WORDS)


Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1039-1046 ◽  
Author(s):  
Kirit M. Ardeshna ◽  
Arnold R. Pizzey ◽  
Stephen Devereux ◽  
Asim Khwaja

Abstract As a dendritic cell (DC) matures, it becomes more potent as an antigen-presenting cell. This functional change is accompanied by a change in DC immunophenotype. The signal transduction events underlying this process are poorly characterized. In this study, we have investigated the signal transduction pathways involved in the lipopolysaccharide (LPS)-induced maturation of human monocyte–derived DCs (MoDCs) in vitro. We show that exposure of immature MoDCs to LPS activates the p38 stress-activated protein kinase (p38SAPK), extracellular signal–regulated protein kinase (ERK), phosphoinositide 3-OH kinase (PI3 kinase)/Akt, and nuclear factor (NF)-κB pathways. Studies using inhibitors demonstrate that PI3 kinase/Akt but not the other pathways are important in maintaining survival of LPS-stimulated MoDCs. Inhibiting p38SAPK prevented activation of the transcription factors ATF-2 and CREB and significantly reduced the LPS-induced up-regulation of CD80, CD83, and CD86, but did not have any significant effect on the LPS-induced changes in macropinocytosis or HLA-DR, CD40, and CD1a expression. Inhibiting the NF-κB pathway significantly reduced the LPS-induced up-regulation of HLA-DR as well as CD80, CD83, and CD86. Inhibiting the p38SAPK and NF-κB pathways simultaneously had variable effects depending on the cell surface marker studied. It thus appears that different aspects of LPS-induced MoDC maturation are regulated by different and sometimes overlapping pathways.


2001 ◽  
Vol 1 (7) ◽  
pp. 1351-1361 ◽  
Author(s):  
Christian M. Kähler ◽  
Andreas B. Pischel ◽  
Thomas Haller ◽  
Christian Meierhofer ◽  
Angela Djanani ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 845
Author(s):  
Robert Kubina ◽  
Marcello Iriti ◽  
Agata Kabała-Dzik

Flavonols are ones of the most common phytochemicals found in diets rich in fruit and vegetables. Research suggests that molecular functions of flavonoids may bring a number of health benefits to people, including the following: decrease inflammation, change disease activity, and alleviate resistance to antibiotics as well as chemotherapeutics. Their antiproliferative, antioxidant, anti-inflammatory, and antineoplastic activity has been proved. They may act as antioxidants, while preventing DNA damage by scavenging reactive oxygen radicals, reinforcing DNA repair, disrupting chemical damages by induction of phase II enzymes, and modifying signal transduction pathways. One of such research areas is a potential effect of flavonoids on the risk of developing cancer. The aim of our paper is to present a systematic review of antineoplastic activity of flavonols in general. Special attention was paid to selected flavonols: fisetin, kaempferol, and quercetin in preclinical and in vitro studies. Study results prove antiproliferative and proapoptotic properties of flavonols with regard to head and neck cancer. However, few study papers evaluate specific activities during various processes associated with cancer progression. Moreover, an attempt was made to collect the majority of substantive studies on bioactive potential of the selected flavonols, especially with regard to modulation of a range of signal transduction pathways that participate in cancer development.


2009 ◽  
Vol 20 (10) ◽  
pp. 2582-2592 ◽  
Author(s):  
Teresa I. Shakespeare ◽  
Caterina Sellitto ◽  
Leping Li ◽  
Clio Rubinos ◽  
Xiaohua Gong ◽  
...  

Both connexins and signal transduction pathways have been independently shown to play critical roles in lens homeostasis, but little is known about potential cooperation between these two intercellular communication systems. To investigate whether growth factor signaling and gap junctional communication interact during the development of lens homeostasis, we examined the effect of mitogen-activated protein kinase (MAPK) signaling on coupling mediated by specific lens connexins by using a combination of in vitro and in vivo assays. Activation of MAPK signaling pathways significantly increased coupling provided by Cx50, but not Cx46, in paired Xenopus laevis oocytes in vitro, as well as between freshly isolated lens cells in vivo. Constitutively active MAPK signaling caused macrophthalmia, cataract, glucose accumulation, vacuole formation in differentiating fibers, and lens rupture in vivo. The specific removal or replacement of Cx50, but not Cx46, ameliorated all five pathological conditions in transgenic mice. These results indicate that MAPK signaling specifically modulates coupling mediated by Cx50 and that gap junctional communication and signal transduction pathways may interact in osmotic regulation during postnatal fiber development.


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